CSU Summer Symposium at UCLA · support of the CSU Summer Symposium at UCLA: Abstracts were received directly from the authors by electronic submission. Every effort has been made

July 25, 20161:00 - 3:30 p.m.

Ackerman Grand Ballroom

CSU Summer Symposium at UCLA

We would like to thank the following for their generous support of the CSU Summer Symposium at UCLA:

Abstracts were received directly from the authors by electronic submission. Every effort has been made to reproduce the content of the abstracts according to the electronic version submitted, ex-cept in certain circumstances where changes were made to comply with standardized format or upon request by the author. Editors do not assume any responsibility for proofreading or correcting any scientifi c, grammatical, or typographical errors.

Photos and video footage taken by UCLA during the CSU Summer Symposium may be used for promotional purposes on behalf of the university.

UCLA Undergraduate Research Center, Sciences

CSU SUMMER SYMPOSIUM AT UCLA Abstract Book

Table of Contents

Welcome Letter i

Schedule of the Day ii

Abstracts 1 - 26

Indices 27 - 30 • Presenter Program Interest 27 - 29• Presenter Institution 30

Welcome to the fi rst annual CSU Summer Symposium and Graduate Program Fair at UCLA!

We are happy to have you join us for an afternoon featur-ing research presentations by students from neighboring CSU campuses, and information sessions on graduate training opportunities in STEM at UCLA. The aim of the Symposium and Fair is to promote scientifi c exchange and provide information on graduate educational opportunities as a way to strengthen interactions between CSU capstone research programs and UCLA graduate programs.

UCLA offers a wide variety of exceptional graduate pro-grams in STEM. The college, with Divisions of Life and Physical Sciences, is located on a single campus with the School of Medicine and hospital. This proximity provides a wealth of research training opportunities and promotes a collaborative and collegial culture of discovery and in-novation that crosses traditional academic boundaries and spans disciplines, departments and schools. Our UCLA STEM community is built on core values of openness, in-clusion, and respect that foster creativity and excellence by embracing a diversity of backgrounds, experience, ideas, and approaches.

We welcome CSU participants and extend thanks to our UCLA graduate program representatives.

Gregory S. Payne, Ph.D.Director, Graduate Programs in BioscienceSenior Associate Dean of Bioscience Graduate Education, David Geffen School of MedicineAssociate Dean of Graduate Education, College of Life Sciences

i

CSU SUMMER SYMPOSIUM AT UCLA Schedule of the Day

1:00 – 1:30 Welcome

1:30 – 2:30 Tabling with concurrent rotating 20-minute information sessions 1:30 – 1:50 Information Session 1 1:50 – 2:10 Information Session 2 2:10 – 2:30 Information Session 3

2:30 – 3:30 Tabling continued with concurrent CSU Poster Session

Poster session will highlight CSU students planning to apply to UCLA who are participating in broaden-ing participation capstone research programs such as MARC, IMSD, MBRS Rise, HMMI and others.

Light refreshments will be served.

ii

1 Identifi cation of Withania somnifera Active Constituents on GABArho Receptors

HODA AHMED, Andrew Li, Narek Darabedian, Feimeng Zhou, Amelia Russo-Neustadt, and Agenor Limon

CSULA, NSF LSAMP Bridge to the Doctorate

Recent scientifi c evidence suggests that hyperexcitability in neural circuits may be responsible for neurodegeneration during aging. This may, in turn, be due to a reduction in GABAergic sig-naling. Thus, developing a way to prevent hyperexcitability in the brain can be an excellent strategy for preventing neuronal death. Withania somnifera (WS) is herbal medicine that is been used in Ayurvedic medicine and is known as an adaptogen because of its stress reducing capability. Our preliminary studies show that whole root WS modulates hippocampal activity and survival via a GABA-mimetic mechanism. In addition, the most widely studied active components of WS root extract, withaferin A and witha-nolide A, were not responsible for the observed GABA receptor activation. Thus, we hypothesize that other key WS constituents promote optimal hippocampal function and neuronal survival via GABAergic mechanism. To test this hypothesis, whole WS ex-tracts have been separated into eight fractions using liquid-liq-uid extraction. To identify bioactive fractions with GABA activity, the Xenopus laevis oocyte model was utilized to study GABArho receptor function. Cloned GABArho cDNA from rat brain was injected into Xenopus oocytes. Two days after injections, GABA currents were recorded from voltage clamped oocytes using microelectrodes fi lled with 3M KCl and membrane potential held constant at -80 mV. Results showed that water and butanol fractions exhibit signifi cant maximal GABA response (One Way ANOVA, p < 0.0001). This fi nding supports our hypothesis that major WS constituents may be responsible for the GABA-mimet-ic activity and have specifi city for GABArho receptors.

1

2 Isolation and Characterization of Human Recombinant T-DARPP

JESUS A. ALDANA-MENDOZA, Philip Farias , Jamil Momand

CSULA, NIH MBRS RISE

The PPP1R1B gene is found to be overexpressed in several types of cancers, including breast cancer. This gene encodes for Dopa-mine and Cyclic AMP regulated phosphoprotein, DARPP-32 and its truncated version, t-DARPP, which has been found to cause resistance in HER-2 positive breast cancer patients undergo-ing treatment with the drug trastuzumab. These proteins have been shown to have several functions based on phosphorylation status of several phosphorylation sites present on each protein. One phosphorylation site on t-DARPP in particular has been found to be correlated with acquired resistance in cancer cells, threonine-39, analogous with threonine-75 on DARPP-32. When t-Darpp is phosphorylated at threonine-39, AKT activation is sus-tained even in the presence of Herceptin, preventing apoptotic processes in the cell. In this project, we want to obtain pure sam-ples of t-DARPP in order to investigate further the signifi cance of the threonine-39 phosphorylation site on the protein’s structure and function and also like to test for cysteine oxidation in order to obtain information about its structural conformation. These experiments will help determine possible mechanism directly linking the protein to the cause of resistance against trastuzum-ab in HER-2 breast cancer patients.

2

3 Mad-linker Phosphorylations Control the Intensity and Range of the BMP-activity Gradient in Developing Drosoph-ila Tissues

ABIGAIL ALEMAN, Marlyn Rios, Matthew Juarez, Daniel Lee, Annan Chen, and Edward Eivers

CSULA

Embryonic patterning is established by growth factor gradients within specifi c tissue fi elds, and cells must interpret these gra-dients to accomplish precise developmental management. An important developmental pathway is the bone morphogenetic protein (BMP) pathway; which instructs embryonic cells to divide, differentiate, or die, while aberrant BMP signaling has been im-plicated in an array of developmental disorders. The BMP signal is propagated intracellularly through C-terminal phosphorylation of its transcription factor Mad, which forms an activity gradient in developing tissues. Here we are interested in how Mad linker phosphorylations control the intensity and duration of the BMP signal in blastoderm embryos and wing imaginal discs. Under investigation are Mad linker serines 204, 208 and 212. Specifi -cally, we want to understand how the combined activity of two kinases, Cyclin dependent kinase 8 (Cdk8) and Shaggy (Sgg) generates a mirroring linker phosphorylation gradient to control the peak intensity and range of the BMP activity gradient. We employed RNA interference experiments in Drosophila cells and tissues to uncover the role of these two kinases. We propose that linker hyper phosphorylation is a cellular mechanism es-sential for regulating the BMP activated Mad (pMad) gradient in developing tissues.

3

4 The Effects of Long Term Treatment with Withania som-nifera on Cognitive Function

SHAZIA ALI, Andrew Li, Jessy Martinez, Leticia Galvez-Alva, Isabel Vasquez, and Amelia Russo-Neustadt


Withania somnifera is an adaptogenic herb that has been tra-ditionally used in the Indian Ayurvedic medical system for thousands of years. It has been found to have many benefi cial properties, such as promoting relaxation, improving muscle strength, and exhibiting neuroprotective characteristics. We hy-pothesize that long-term treatment with Withania somnifera will improve the performance of older rats in cognitive/behavioral tasks, and will also increase the expression of genes associated with learning and memory. The novel object recognition test was employed in our studies. Briefl y, Sprague-Dawley rats were placed in an open fi eld arena in the presence of two objects, one of which was novel after a 24-hour delay. Rats that were treated with Withania somnifera for fourteen months showed an increase in environmental engagement and higher discrimina-tion index during the novel object recognition test. It was found that Withania somnifera treated rats had a mean discrimination index of 0.36 ± 0.05, while the mean discrimination index of the control group was 0.12 ± 0.03 (p = 0.0013). In order to assess the changes in gene expression during the course of the treat-ment, RTqPCR analysis of hippocampi from these animals were conducted. RTqPCR was performed with the SYBR Green mix from Bio-Rad and an iCycler real-time PCR machine. Our analy-sis revealed an elevation in the expression of glutamate AMPA receptor 2 (p=0.015, n=8). These results suggest that long term Withania somnifera treatment preserves recognition memo-ry and environmental exploration/engagement, and may also enhance gene expression associated with excitation/inhibition balance in the CNS.

4

5 The effect of mitochondrial alternative oxidases and type II NAD(P)H dehydrogenases on reactive oxygen species pro-duction in Arabidopsis thaliana

Nickolas Allen, Daniel Geiszler, MAYLIN CALDWELL, and Matthew Escobar

CSUSM, NIH MARC

The mitochondrial electron transport chain (ETC) plays a cen-tral role in the bioenergetics of all eukaryotic cells. However, the structure of the ETC varies somewhat between plants and animals. Plants have a more branched ETC, providing alter-native pathways for electron fl ow, including type II NAD(P)H dehydrogenases (ND) and alternative oxidases (AOX). Recent studies suggest that these “alternative respiratory pathways” may help to minimize the production of reactive oxygen spe-cies (ROS) by the ETC. to better understand the connections between ETC structure and ROS production in plants, we have constructed two RNAi vectors designed to silence all AOX genes (5 total) or all external ND genes (NDout) (4 total) in Arabidop-sis thaliana. These vectors were used to generate a series of transgenic A. thaliana lines. Real time RT-PCR analyses demon-strated signifi cantly reduced levels of target AOX and NDout transcripts in several transgenic lines. In vivo respiratory assays of AOX-silenced lines showed signifi cantly reduces AOX capacity (~40% reduction) compared to wild type. However, we saw no signifi cant decrease in external NADH or NADPH oxidation in mitochondria isolated from NDout-silenced lines, despite re-duced transcript levels. Hydrogen peroxide production and lipid peroxidation levels were measured in AOX and NDout silenced lines. One AOX-silenced line showed a >50% increase in H2O2 content in both whole leaf tissue and in isolated mitochondria as well as signifi cantly higher levels of total lipid peroxidation. Overall, this project will substantially increase our understanding of mitochondrial-associated ROS production, which is central to the fi eld of biology.

5

6 Determination of the Oncogenic Potential of t-DARPP through a Focus Formation Assay

CLARA T. CANO, Jamil A. Momand


The PPP1R1B gene codes for the dopamine and cAMP-regulated phosphoprotein, DARPP-32 and its truncated isoform, t-DARPP. DARPP-32 is known to mediate dopamine response signals in neuronal cells, however, its role outside the brain is unknown. t-DARPP has the same sequence as DARPP-32 except that it is shortened by 36 amino acids at the N-terminus. t-DARPP is over-expressed in adenocarcinomas the breast, prostate, stomach and colon. t-DARPP causes trastuzumab resistance in HER2+ breast cancer cells. In an attempt to determine if t-DARPP is an onco-gene, a focus formation assay (FFA) will be employed. A FFA test will use the introduction of t-DARPP as a potential oncogene to determine if morphological transformation occurs as assessed through the formation of a dense multi-layer of cells, which is a known characteristic of oncogenicity in vitro. The PCR product of three separate protein coding genes (t-DARPP, H-ras and c-myc) will be cloned into the pcDNA 3.3-TOPO vector to ensure high expression levels in adherent mammalian tissue culture cells. Rat embryo fi broblasts will be transfected with combinations of plasmids and a FFA will be used to determine potential oncoge-nicity. Currently, only t-DARPP has been successfully cloned into the expression vector. This project will test whether t-DARPP has oncogenic potential.

6

7 Probing the Interactions Between Calcium Carbonate Crystals and a Beetle Antifreeze Protein Using an Engineered Antifreeze Protein

JOSE O. CASTELLON and Xin Wen


Antifreeze proteins (AFP) are widely known for their ability to inhibit ice crystal formation and are characterized by lowering the freezing point of water without changing the melting point. A new role for beetle AFPs in controlling the formation of calci-um carbonate crystals has been recently reported by our labo-ratory. Charged residues on the surface of the AFPs are spec-ulated to be important for this new role. In this study, a beetle AFP mutant with a signifi cantly reduced positive surface charge was prepared. The effects of the mutant on calcium carbonate crystallization were then investigated and compared to those of the wild-type AFP using pH, absorbance, and zeta potential assays. The results shed lights on the molecular mechanism of this novel function of AFPs. The achieved structural information will be useful for designing next-generation of antiscalants and anticaking agents.

7

8 Thread-Based Microfl uidics: A Step Towards Point-of-Care (POC) Diagnostic Devices

NATHALIE A. DEL ROSARIO, and Frank A. Gomez


Low-cost point-of-care (POC) diagnostic devices are needed in both developed and resource limited countries. Thread-based microfl uidics can provide an alternative to traditional devices for use in a variety of analytical assays achieving similar accuracy and sensitivity as these traditional techniques. Past studies have shown that that fl uid fl ow in thread can be easily manipulated using knots, sewing, and weaving to cause controlled mixing and separation required in many biological assays. Herein, we de-scribe the use of a thread-based platform to monitor and quan-tify lactate in a double enzyme catalyzed fl uorescent-based reac-tion. Here, lactate dehydrogenase (LDH) and diaphorase (DI) are utilized in a coupled reaction and the conversion of resazurin to fl uorescent resorufi n is monitored which is correlated to lactate.

8

9 Analyzing free-living phenotypes resulting from the over-expression of smc00658 and sma5027 in S. meliloti.

CRISELDA J. DILLAGUE, David J. Eng, and Esther J. Chen

CSUF, NIH MARC

ExoS/ChvI is a bacterial two-component signaling pathway that regulates genes that are required for the formation of an endo-symbiotic relationship between Sinorhizobium meliloti and its host plant Medicago sativa. The bacteria provide fi xed nitrogen for the plant and in return, the plant provides carbon sources. Among the genes transcriptionally regulated by ExoS/ChvI are sma5027 and smc00658. The sma5027 gene encodes a putative protein with an unknown function. The smc00658 gene encodes a putative transcriptional regulator from the LuxR family. To investigate the function of these genes, we examined pheno-types resulting from overexpression of these genes. We gen-erated overexpression plasmids for each gene and conjugated them into an S. meliloti wild type and a partial-loss-of-function chvI mutant strain. We then plated the overexpression strains onto different media to test nutrient utilization, succinoglycan production, motility, cell envelope integrity, and growth in acidic conditions. We discovered that overexpression of sma5027 does not affect the wild-type strain, but does worsen growth on rich media and worsen the cell envelope integrity defect of the chvI partial loss-of-function mutant. The overexpression of smc00658 in wild-type results in a growth defect on acidic media while overexpression in the chvI mutant results in decreased growth on rich media and acidic media. Our data demonstrates that overexpression of sma5027 and smc00658 infl uences free-living phenotypes of S. meliloti. In future experiments, knockout strains will be constructed and tested for their ability to form symbioses to gain more insight into the function of these genes.

9

10 Dissecting Functions of the Turnip yellows virus Sup-pressor of RNA Silencing P0 in Evasion and Elicitation of Plant Defenses

DUGHBAJ, M.A., Valdez, K., Wang, K.D., Nguyen, T.T.V., Oza, S.V., & Sacco, M.A.

CSUF, NIH MARC

The Turnip yellows virus (TuYV) protein P0 (P0Tu) is a viral sup-pressor of RNA silencing (VSR) that targets Argonaute (AGO) proteins for degradation. P0Tu is also recognized in Nicotia-na glutinosa accession TW59, in which it elicits hypersensitive response (HR) and resistance to TuYV. We are interested in understanding how P0Tu interacts with the host plant cell as a VSR versus an elicitor of HR. To identify amino acids that are critical for these activities, P0Tu has been subjected to serial deletion analysis and site-directed mutagenesis at either several conserved sites or by systematic substitutions with the 6 amino acid sequence NAAIRS along the entire length of the coding sequence. We predicted that the modifi cations could potentially cause loss of VSR activity in Nicotiana benthamiana and/or loss of HR activation in N. glutinosa to dissect these two functions. Mutant clones were co-infi ltrated with GFP into the leaves of N. glutinosa accession TW59 and N. benthamiana to observe for suppression of RNA silencing and induction of cell death. Substitution of two conserved central arginine residues with lysine caused P0Tu to activate more rapid and robust HRs on N. glutinosa. Deletion or mutation of the amino terminus inac-tivated P0Tu, while modifi cations within or deletion of the last 22 carboxy-terminal amino acid residues (227-249) resulted in mutants that maintained VSR activity, but had impaired ability to elicit HR on N. glutinosa, suggesting that P0 activities in sup-pression of silencing and elicitation of HR may be distinct.

10

11 Training induced muscular adaptations associated with improved cardiometabolic profi les in individuals with spinal cord injury (SCI)

STEVE GUZMAN, Stefan Keslacy, Katrina Yamazaki, Christine Dy


Activity based therapies that target spinal locomotor networks have been associated with improvements in walking ability with varying levels of success after traumatic SCI. A typical regimen of locomotor training exposes the paralyzed individual with prolonged, full-body, load-bearing exercise of moderate inten-sity. The purpose of this pilot study is to investigate whether improved function of skeletal muscle mitochondria could explain the interaction between how locomotor training promotes dual benefi ts to the neuromuscular and cardiometabolic systems. We hypothesize that activity-based training that elicits pronounced electromyographic activity will trigger improvement in mito-chondrial oxidative capacity (MOC) and overall improvement in resting metabolic rate and oxidative respiration during activity. Methods: The participant will complete a 3 month regimen of locomotor training using a body weight support and treadmill system (BWST) and strength training exercise ( 30 mins each, 3x/week). Surface EMG activity of the calf and quadriceps muscles was assessed before and after training. At similar time points and in the same muscles, rate constants indicative of skeletal muscle MOC were determined using near infrared spectroscopy. Blood samples were collected to determine whether changes in performance or resting measures were associated with overall improvement in cardiometabolic health. Anticipated Results: Baseline measurements were lower compared to able-bodied, healthy adults. Training induces changes in EMG activity and MOC data that were indicative of overall health benefi t. Con-clusion: The case study provides promising result in our search to determine how activity-based therapies are able to promote recovery neuromuscular function, skeletal muscle aerobic capaci-ty, and overall cardiometabolic health.

11

12 Identifi cation of a novel Cripto/MyosinII interaction that promotes stem cell mediated tissue regeneration

MALACHIA Y. HOOVER, Evan Booker, Caroline Arellano-Gar-cia, Erika Duell, Wolfgang Fischer, Peter Gray, Jonathan A. Kelber

CSUN, NIH MBRS RISE

Stem cells are necessary for proper development, tissue homeo-stasis and regeneration, and dysregulation of their activity can lead to various diseases including diabetes, neurodegeneration and cancer. In this regard, we hypothesize that the stem cell marker, Cripto, is a potential regulator of tissue regeneration. Cripto is a cell surface glycoprotein and the founding member of the ECF-CFC protein family. However, the function and mech-anisms of action of Cripto during tissue regeneration are not yet understood. In order to evaluate the mechanisms by which Cripto regulates regeneration, we sought to identify novel Crip-to-binding proteins using immunoprecipitation and proteomics methods. Here we identifi ed non-muscle myosin IIs (MYH9/10) as prominent Cripto binding proteins. MYH9/10 are known to regulate the actin cytoskeleton dynamics and wound healing functions. Thus, we tested if Cripto and MYH9/10 cooperate to promote stem cell survival/proliferation and migration during tissue regeneration and wound healing using biochemical, cell biology and in vivo methods. We demonstrate that the zebrafi sh orthologs of Cripto and MYH9, oep and myh9l1, respectively, are upregulated during adult zebrafi sh caudal fi n regeneration in concert with bona fi de adult stem cell markers. Using the juvenile zebrafi sh tail bud regeneration model, we have further discovered that inhibition of oep or myh9l1/2 blocks stem cell mediated tissue regrowth. We also fi nd that the release of sol-uble Cripto from mammalian cells is dependent upon MYH9/10 function. Future studies will explore the cooperative function of both Cripto and MYH9/10 across vertebrates using both in vitro and in vivo methods.

12

13 High-Throughput Sample Generation for Single Mole-cule FRET Studies of Protein Folding

JESSE J. HOWE, Wilfredo Parker, Gregory V. Walters, Made-line Jensen, Kambiz M. Hamadani

CSUSM, Summer Scholars

Understanding the short-lived conformational states populated by proteins during folding is an on-going hot topic in biochem-istry. Single molecule fl uorescence resonance energy transfer (smFRET) reports on the relative distance between two fl uo-rophores attached at specifi c sites on proteins of interest, and can also help to illuminate conformational dynamics. Here we outline a method that enables the parallel generation of various dual-labelled protein and ribosome-bound nascent chain (RNC) constructs for smFRET-based protein folding studies. We use a PCR-based cloning approach to create mutants of a Barnase gene, then in-vitro transcription/translation to express proteins containing bio-orthogonal unnatural amino acid tags, and fi nally we attach dyes using a copper-catalyzed azide-alkyne cycload-dition reaction (a.k.a. click chemistry). Since every step is both parallelizable and effi cient this method allows large libraries of proteins to be generated for smFRET-based screens.

13

14 Adenylate Kinase 4 Expression Regulates the mTORC1 Pathway to Promote HeLa Cell Proliferation

CANDICE B. LARSON and Nathan J. Lanning


Signal transduction pathways are important for regulating cell proliferation. Aberrantly activated or deactivated proteins within these pathways affect cell abundance and contribute to vari-ous cancers. The mTORC1 pathway is well characterized and known to assist in producing essential components required for normal cell proliferation. Numerous studies demonstrate that hyper-activation of mTORC1 signaling contributes to cell pro-liferation; however, not all of the key components that activate mTORC1 are known. Recent evidence suggests that suppressing the expression of a mitochondrial protein, adenylate kinase 4 (AK4), activates the mTOCR1 pathway and therefore increases the cell-cycle progression. To further characterize the effects of AK4 on the mTORC1 pathway, AK4 expression will be suppressed and the activation of proteins downstream mTORC1 (S6Kinase and S6) and mTORC1-responsive cell cycle regulator (cyclin D1) protein in HeLa cell will be assessed. AK4 is a modulator of the mTORC1 signal transduction pathway because inactive AK4 has been identifi ed in various types of cancers. I hypothesize that AK4 expression modulates the effects of mTORC1 signaling and therefore effects cell proliferation. This work will advance our understanding of how AK4 interacts with cell signaling pathways and how it impacts cell proliferation.

14

15 The Role of CNTNAP2 in Interneuron Development

JESSY D. MARTINEZ, and Laura A. Cocas


Autism spectrum disorders (ASD) are neurodevelopmental disorders that manifest during early infancy and are character-ized by impaired social communication and restrictive, repeti-tive behaviors. Children affected with ASD have a compromised cerebral cortex that affects social, cognitive, and motor functions driven by inhibitory interneurons. These inhibitory interneurons are responsible for information processing, forming synaptic connections, and sustaining the balance of excitatory and in-hibitory activity within the cortex. Recent investigations in ASD have found an imbalance of neuronal excitation and inhibition during development and mouse model studies have demon-strated inhibitory interneuron abnormalities in the cortex of the maturing brain. Several investigations have also identifi ed genes associated with ASD, including contactin-associated protein-like 2 (CNTNAP2) a cell adhesion protein and member of the neu-rexin family. CNTNAP2 defi cient mice exhibit core behavioral defi cits of ASD such as abnormal social interactions and possess decreased inhibitory neurotransmission and loss of interneurons in the adult brain. Currently, the mechanisms by which these interneuron defects occur during development in the absence of CNTNAP2 are unclear. Using a combination of histological tools, we will examine the proliferation, migration, and differentiation of inhibitory interneurons during development in a model with the CNTNAP2 mutation. Here, the hypothesis is that CNTNAP2 defi cient mice will demonstrate abnormal progressive pattern-ing of cortical interneurons during embryonic development and post-natally show atypical interneuron displacement in the cere-bral cortex. Results from this investigation will help provide new insight to brain circuitry alterations during early development in children affected with ASD.

15

16 Investigating the modulation of serine-10 phosphoryla-tion by arginine-8 methylation in histone H3

ARON JUDD P. MENDIOLA, Mariel Mendoza, Cecilia Zuri-ta-Lopez

CSULA, NSF LSAMP

Histone proteins are involved in the expansion and condensation of DNA and are modulated by certain post-translational modifi -cations (PTMs) in order to perform their functions. The serine-10 residue of histone H3 is located at the N-terminus within an RKS motif, comprised of arginine-8, lysine-9 and serine-10. Although it is an established mark of mitosis, abnormal phosphorylation of serine-10 in histone H3 is known to activate expression of c-fos and c-jun, two proto-oncogenes overexpressed in a variety of cancers. Previous work has shown that phosphorylation of serine-10 prevents heterochromatin protein 1 (HP1), a protein involved in gene repression, from binding to tri-methylated lysine-9, thus alluding to a ‘methyl/phos switch.’ In addition, a computational study shows that arginine-8 and serine-10 mod-ifi cation are involved in crosstalk within an RKS motif. We pro-pose that in addition to lysine-9 methylation, the methylation of arginine-8 can modulate phosphorylation of serine-10. Prelimi-nary studies by our lab show that phosphorylation of serine-10 modulates arginine-8 methylation. Through autoradiography and chromatography analyses, we aim to determine how meth-ylation affects phosphorylation within the RKS motif of histone H3. Investigating the inhibition of phosphorylation by methyla-tion of neighboring arginine residues can contribute to under-standing cellular signaling in proteins containing an RKS motif.

16

17 Identifi cation and Characterization of a Minimal Func-tional Splicing Regulatory Protein, PTBP1

ROBERT J. ONTIVEROS, Justin Doan, Adrian L. Hernandez, Douglas L. Black, and Niroshika M. Keppetipola

CSUF, NIH MARC

In higher eukaryotes, alternative splicing of a gene transcript into multiple fi nal mRNA isoforms contributes signifi cantly to the diversity of the cellular proteomes. The process of alternative splicing is regulated partly by RNA binding proteins which bind pre-mRNA to modulate splice site selection. Splice variants have been identifi ed in many neurodegenerative diseases and cancers, underscoring the importance of alternative splicing. Polypyrim-idine Tract Binding Protein 1 (PTBP1) is an RNA binding protein that functions as a splicing regulator. PTBP1 contains four RNA Recognition Motifs (RRMs) joined via three linker regions Each RRM binds to pyrimidine-rich sequences with varying affi nity and structural preferences. Understanding how PTBP1 binds to its target RNA and the role of each RRM during exon inclusion/exclusion hinges on obtaining an atomic structure of full-length PTBP1 bound to a target RNA. RNA-bound PTBP1 crystallization trials have been hindered by the fl exible linker regions between RRMs 1 and 2, and RRMs 2 and 3. The aim of this study is to identify and characterize a minimal functional PTBP1. A series of PTBP1 mutants were created with deletions in linker 1 (∆19, ∆29, ∆37, ∆40) as well as linker 2 (∆21, ∆44, ∆53, ∆68). Mutants were tested in cell culture for protein expression and splicing repres-sion activity. Western blots indicate that the mutant proteins are well expressed. Splicing assays on two PTBP1 regulated exons reveal that the shortest construct (linker 1∆40 and linker 2 ∆68) maintains splicing repression activity similar to full-length PTBP1.

17

18 Landscape Genomics of an Endangered Vernal Pool Crustacean (Lepidurus packardi) Endemic to Central Valley, California

GABRIELA S PEREZ, and Andres Aguilar


Understanding the distribution of spatial genetic structure is key in successful conservation planning and management strategies for endangered and threatened species. Habitat fragmentation and conversion of vernal pools, seasonally inundated wetlands, have caused conservation concerns for many endemic species specifi cally adapted to these ecosystems in California. The tadpole shrimp (Lepidurus packardi) is currently listed as endan-gered under the Endangered Species Act and is considered a key stone species. To gain a better understanding about the land-scape level structure of Lepidurus packardi, we aim to (1) deter-mine the patterns of local adaptation based on environmental distance and (2) determine the patterns of gene fl ow based on geographic distance. This study will be conducted by using double-digest Restriction-Site Associated Digestion sequencing (ddRADseq) in conjunction with soil data to determine the roles of isolation by distance and isolation by environment. The use of Principle Components Analysis (PCA) will assess the distribution of populations by spatially representing environmental and ge-netic variables. These results will highlight the dispersal capabili-ties and geographic variation between pools of Lepidurus pack-ardi. Our fi ndings will be useful in planning future restoration efforts and defi ning conservation priorities for this species.

18

19 Lipid Accumulation in Airway Mucosa from Patients with Chronic Rhinosinusitis

NICOLETTE D. POLLOCK, Sandy Alvarez, Jivianne Lee, Edith Porter

CSULA, NIH MARC

Background: Epithelial cells lining the respiratory tract contrib-ute to the fi rst line of mucosal defense through the production of antimicrobial peptides and initiation of the adaptive immune response. Recent evidence suggests that antimicrobial lipids are induced in sinus mucosa from patients with chronic rhinosinusitis (CRS) but the cellular source of these lipids is unclear. Histolog-ical assessment of lipids is impaired by routine processing that strips native lipids from tissues but is enabled by pretreatment with the linoleic acid (LA) and chromic acid (CA) to amplify and retain lipids during tissue processing. Objectives: To implement LA/CA pretreatment for assessment of lipid accumulation in for-malin fi xed sinus tissues from patients with and without chronic rhinosinusitis with the lipophilic dyes Nile Red and Oil-Red-O. Results: Pretreatment with LA/CA preserved lipids in epithelial cells and in sinus mucosa as refl ected by Nile Red fl uorescence and Oil Red-O signals, respectively. Furthermore, we found that in 4/5 non-CRS controls, the respiratory epithelium was more prominently stained with Nile Red whereas in 7/8 CRS samples, submucosal tissue was more prominently stained and contained numerous cells with granular lipid accumulation, reminiscent of macrophages. Conclusion: In CRS, macrophages may be recruit-ed to the site of infection delivering antimicrobial lipids.

19

20 Targetable MRI Contrast Agents Using Tetrakis(amino-methyl)adamantane as a Scaffold

ELISEO E. QUIROZ, Carlos Gutierrez


Magnetic resonance imaging (MRI) contrast agents have be-come benefi cial tools in the diagnosis of cardiovascular disease as they contrast images of the vasculature to assess abnormali-ties. Contrast agents, such as Gd(III) complexes, catalytically relax surrounding water molecules in vivo producing three-dimen-sional images from their spatial distribution. Novel MRA contrast agents are being designed around an effort to exhibit high relax-ivity at high magnetic fi elds (~7 T) to generate high-resolution images. The relaxivity can be defi ned as the rate at which a metal complex changes the relaxation time of coordinated water mol-ecules; with regard to their application, it defi nes their effi cacy. Targetable contrast agents have shown increased relaxivity, while bound, from an increase in rotational correlation times. When the contrast agent binds a receptor on a target molecule, it takes on a rotational correlation time that is similar to that of the molecule. With an optimal rotational correlation time, the Gd(III) complex can exchange water molecules with the metal center at an optimized rate generating contrast on an image. One obsta-cle that has yet to be achieved is reaching the theoretical max-imum relaxation enhancement per Gd(III) ion (~100 mM-1 s-1). If slowing down the molecular tumbling (increase rotational cor-relation time) of the contrast agent with a two-point attachment, an increase in relaxivity should be observed by the optimization of water exchange. We hypothesize a MRA contrast agent can be functionalized around tetrakis(aminomethyl)adamantane that targets human serum albumin (HSA) with a two point attach-ment (divalent) to exhibit increased rotational correlation time.

20

21 Photon Orbital Angular Momentum Pinhole Mapping

EDWARD B RAMIREZ, David Van Buren, and Susan Terebey


Photons, the carriers of electromagnetic radiation are known to possess intrinsic angular momentum of amount ±h, which is responsible for spin polarization. However, in recent decades we have come to know that photons can also possess extrin-sic angular momentum, which is also known as orbital angular momentum (OAM). Photons travel at the speed of light, have energy that is dependent on their frequency, and carry angular momentum. These characteristics set two length scales, one is the wavelength, and the other is a length scale associated with angular momentum. The question arises, what is the physical meaning of this angular momentum (transverse) length scale? We are exploring this question through our tabletop experi-ments using different OAM states generated via fork holograms (FH) interacting with different pinholes. The idea being if the hole is small enough or the photon has too large a transverse dimension, the photon will not pass through. Our aim is to study different OAM states with the help of an engineered automated apparatus for precise measurements.

21

22 Probing the Role of Threonine-221 and Lysine-397 in ADP-Glucose Pyrophosphorylase from Deinococcus radiodu-rans

JANICE REYNAGA, Gabrielle Szczeblowski, Ashley Le-Pham, Leonard Ong, Dr. Andrew Orry and Dr. Christopher R. Meyer

CSUF, NIH MARC

While starch is commonly found in our diet, it also serves as the backbone for several other commercial products because of its unique properties as a biopolymer. Optimizing starch production would change the environmental impact these industries have, as well as allow a new market for renewable and biodegrad-able products to emerge. Understanding the structure-function relationships among the ADP-Glucose Pyrophosphorylases (ADP-Glucose PPases) allow us to begin protein-engineering studies with the goal of producing a highly active form of the enzyme. ADP-Glucose PPase is an allosterically regulated en-zyme that serves as the rate-determining step of starch syn-thesis. The enzyme of interest is derived from the extremophile bacterium Deinococcus radiodurans (D. rad), which could confer transgenic crops harboring this form of ADP-Glucose PPase with added starch biosynthesis ability in extreme environmental con-ditions. The K397A and T221A enzymes were generated to probe the importance of certain amino acids at the allosteric site and glucose-1-phosphate (G1P) binding site, respectively. Prelimi-nary studies with K397A indicate lower apparent binding affi nity for activators and overall lower enzyme activity. These results demonstrate the importance of a positively charged amino acid at this position. D. rad enzyme contains a threonine at a posi-tion near the G1P binding site, unlike other ADP-Glucose PPase strains that hold an alanine at this analogous position. An effec-tor screening indicated T221 is highly sensitive to metabolites compared to wild type. Further kinetic characterization of this enzyme involves G1P saturation in the presence of activators. Supported by NSF BIO MCB grant #0448676 and NSF BIO-DBI.

22

23 Glioma Cell Proliferation Promoted by AK4 Regulated mTOR Pathway Activation

JOSHUA SILVA and Nathan Lanning


A hallmark of cancer cell biology is the dysregulation of signal-ing pathways that manage cancer associated phenotypes such as proliferation and survival. One dysfunctional pathway in cancers is the mechanistic target of rapamycin (mTOR). mTOR signaling allows for transitions between metabolic states by responding to environmental signals and controlling processes that regulate energy. Recently, the expression of an Adenylate Kinase 4 (AK4) has been identifi ed as modulating cellular bioenergetics through the activation of pathways such as mTOR, resulting in both en-hanced proliferation and activation of stress-responses. Addi-tionally, reduced AK4 levels have been observed to be altered in human glioma cells, meanwhile the mTOR pathway is hyperac-tive. We hypothesize that AK4 expression regulates mTOR acti-vation and induces downstream effects that promote glioma cell biology. To determine if AK4 expression affects mTOR activity, healthy cells and glioma cell lines will be transfected with ex-pression vectors of AK4 or siRNA knocking down AK4 transcripts. Post-transfection, phospho-specifi c modifi cations of activators and inhibitors upstream of the mTOR pathway and its down-stream targets will be assessed by Western blot and immunofl u-orescence assays. I expect to identify that AK4 expression has a regulatory role on the activation status of the mTOR pathway. By identifying the regulatory role of AK4, we hope to elucidate the therapeutic potential of modulating AK4 levels in cancer cells.

23

24 Effects of Antifreeze Protein from Cold-Adapted Beetle on Thermal Protection of Lactate Dehydrogenase

REBECCA ELIZABETH VARGAS, Bianca Yaghoobi, Xin Wen


Previous studies have demonstrated the presence of transcripts of AFP genes in a summer desert beetle Microdera punctipen-nis, where its AFPs (MpAFPs) have a thermal protective function, suggesting a novel AFP protective mechanism. The widely stud-ied AFPs from cold-adapted beetles include AFPs from Dendroi-des canadensis (DAFPs) found at high levels in the insect’s winter hemolymphs and have very similar tertiary structures to that of MpAFP. We hypothesize that DAFP-1 will exhibit similar thermal protective behaviors to MpAFPs. This hypothesis will be tested by preserving the enzymatic activity of lactate dehydrogenase (LDH). DAFP-1 will be purifi ed and isolated using our previously published procedures. Standard enzymatic assays will be per-formed on the model LDH, before and after thermal treatments at different temperatures (46, 50, and 60 °C) as well as in the presence of DAFP-1. The data will be compared and analyzed and the effects of the DAFP-1 on the thermal protection of the enzyme will be demonstrated. The thermal protective mecha-nism by the AFP will be discussed and suggested in this work

24

25 Detection of Phosphorus Oxyanions in Different Matri-ces Using IC-ESI-MS

MARIA GUADALUPE VAZQUEZ DE VASQUEZ, and Krishna Foster


The establishment of a sensitive and selective method for the detection of reduced phosphorus oxyanions is vital for under-standing the phosphorus cycle. This study aims to quantify re-duced phosphorus species in different matrices (i.e. Precambrian carbonates and geothermal creek soil). Ion chromatography (IC) coupled with electrospray mass spectrometry (ESI-MS) has been successfully used to identify and quantify reduced phosphorus oxyanions, in natural geothermal water, termite extract superna-tant, and synthetic schreibersite corrosion samples.1,2 Optimal suppressed ion chromatography conditions include the use of a 15 μL injection loop and a AS17 HC analytical column. We expect to obtained similar limits of detection as previous studies.1, 3 Moreover, we expect to obtain results that confi rm the presence of phosphite in these samples. We hypothesize higher concen-trations of phosphite in geothermal creek soils than the previ-ously analyzed geothermal water. The quantifi cation of reduced phosphorus species would shed light on the understanding of phosphorus cycle and the introduction of phosphorus to biolog-ical systems.

25

26 Absorption vs. Extinction: Solutions to Particles

NHU Q. VU and Paula K. Hudson

CSUF, HHMI

Atmospheric aerosol particles have a large and indeterminate ef-fect on the Earth’s climate. Incoming solar radiation and outgo-ing terrestrial radiation can directly interact with aerosol particles which can scatter or absorb the radiation. This process can result in either a cooling effect on the Earth’s surface, where incoming solar radiation is scattered back to space or a warming effect, where outgoing infrared terrestrial radiation can be absorbed and reemitted back to the Earth’s surface. Radiative transfer cal-culations, a quantifi cation of the radiative effects, are dependent on absorption and extinction parameters which are dependent on the chemical composition and phase of the aerosol particle. In this study, the optical properties of short chain C2 – C6 a, w-dicarboxylic acids are measured using infrared radiation. Four particular acids- oxalic, malonic, succinic, and glutaric acid, and mixtures thereof, have been characterized as a function of con-centration in the infrared fi ngerprint region from 1500 – 1000 cm-1 using a Fourier transform infrared (IR) spectrophotometer with an attenuated total refl ectance cell (FTIR-ATR). In the aque-ous phase, observed changes in the absorption spectra of the in-dividual acids and mixtures with concentration are in agreement Beer’s Law and the corresponding additive property, respective-ly. When solutions undergo liquid to solid phase change, prom-inent IR peaks in the fi ngerprint region sharpen and a decrease in the OH stretching region from 3500 – 3000 cm-1 is observed. The changes in the infrared region with corresponding phase change and resulting implications on Earth’s radiation balance will be discussed.

26

Presenter Program Interest

Biochemistry, Biophysics & Structural Biology 2 Jesus Aldana-Mendoza 5 Maylin Caldwell 6 Clara Cano 7 Jose Castellon 8 Nathalie Del Rosario 13 Jesse Howe 16 Aron Judd Mendiola 17 Robert Ontiveros 22 Janice Reynaga 24 Rebecca Vargas 26 Nhu Vu

Bioinformatics 17 Robert Ontiveros

Cell & Developmental Biology 2 Jesus Aldana-Mendoza 3 Abigail Aleman 6 Clara Cano 12 Malachia Hoover 14 Candice Larson 19 Nicolette Pollock 23 Joshua Silva

Gene Regulation 2 Jesus Aldana-Mendoza 6 Clara Cano 9 Criselda Dillague 12 Malachia Hoover 16 Aron Judd Mendiola 17 Robert Ontiveros 19 Nicolette Pollock

27


Genetics & Genomics 2 Jesus Aldana-Mendoza 9 Criselda Dillague 12 Malachia Hoover 16 Aron Judd Mendiola 17 Robert Ontiveros 19 Nicolette Pollock

Immunity, Microbes & Molecular Pathogenesis 2 Jesus Aldana-Mendoza 6 Clara Cano 9 Criselda Dillague 10 Mansour Dughbaj 14 Candice Larson 16 Aron Judd Mendiola 19 Nicolette Pollock 22 Janice Reynaga 24 Rebecca Vargas

Molecular, Cellular & Integrative Physiology 3 Abigail Aleman 6 Clara Cano 11 Steve Guzman 16 Aron Judd Mendiola 17 Robert Ontiveros 22 Janice Reynaga 23 Joshua Silva 24 Rebecca Vargas 26 Nhu Vu

28


Molecular Pharmacology 2 Jesus Aldana-Mendoza 6 Clara Cano 10 Mansour Dughbaj 14 Candice Larson 22 Janice Reynaga 23 Joshua Silva

Neuroscience 1 Hoda Ahmed 2 Jesus Aldana-Mendoza 4 Shazia Ali 11 Steve Guzman 15 Jessy Martinez 16 Aron Judd Mendiola 22 Janice Reynaga

Chemistry 7 Jose Castellon 8 Nathalie Del Rosario 20 Eliseo Quiroz 25 Maria Vazquez de Vasquez

Ecology & Evolutionary Biology 5 Maylin Caldwell 18 Gabriela Perez

Engineering 3 Abigail Aleman 21 Edward Ramirez

Atmospheric & Oceanic Sciences 25 Maria Vazquez de Vasquez

29

Presenter Institution

California State University, Fullerton 9 Criselda Dillague 10 Mansour Dughbaj 17 Robert Ontiveros 22 Janice Reynaga 26 Nhu Vu

California State University, Los Angeles 1 Hoda Ahmed 2 Jesus Aldana-Mendoza 3 Abigail Aleman 4 Shazia Ali 6 Clara Cano 7 Jose Castellon 8 Nathalie Del Rosario 11 Steve Guzman 14 Candice Larson 15 Jessy Martinez 16 Aron Judd Mendiola 18 Gabriela Perez 19 Nicolette Pollock 20 Eliseo Quiroz 21 Edward Ramirez 23 Joshua Silva 24 Rebecca Vargas 25 Maria Vazquez de Vasquez

California State University, Northridge 12 Malachia Hoover

California State University, San Marcos 5 Maylin Caldwell 13 Jesse Howe

30

Documents

CSU Summer Symposium at UCLA · support of the CSU Summer Symposium at UCLA: Abstracts were received directly from the authors by electronic submission. Every effort has been made