CELL TO CELL JUNCTIONS BY: ASHLEY COHN

SURFACE MARKERS

STRUCTURE

VARIABLE, INTEGRAL OR GLYCOLIPIDS

IN PLASMA MEMBRANE.

FUNCTION

IDENTIFY THE CELL

EXAMPLE

MHC COMPLEXES,

BLOOD GROUPS, ANTIBODIES

SEPTATE JUNCTIONS/ TIGHT JUNCTIONS

STRUCTURE

TIGHTLY BONDED, LEAK PROOF,

FIBROUS CLAUDIN PROTEIN THAT

SEALS THE CELL

FUNCTION

HOLDS CELL TOGETHER SO

THAT MATERIALS PASS THROUGH

BUT NOT BETWEEN THE CELLS

EXAMPLE

JUNCTIONS BETWEEN

EPITHELIAL CELLS IN THE

GUT

ADHESIVE JUNCTION(DESMOSOME)

STRUCTURE

VARIENT CADHERINS, DESMOCOLLINS,

BIND TO INTERMEDIATE FILAMENTS OF

CYTOSKELETON

FUNCTION

CREATES STRONG FLEXIBLE

CONNECTIONS BETWEEN CELLS,

FOUND IN VERTEBRATES

EXAMPLE

EPITHELIUM

• CADHERIN IS A PROTEIN WHICH IS A CA2+

DEPENDENT ADHESION MOLECULE WITH VERY WIDE POLYGENETIC DISTRIBUTION.

• DESMOSOMES ARE A CADHERIN BASED JUNCTION UNIQUE TO VERTEBRATES. THEY CONTAIN THE CADHERIN'S DESMOCOLLIN.

ADHESIVE JUNCTION ( ADHERENS JUNCTION)

STRUCTURE

CLASSIC ADHERINS BIND

TO MICROFILAMENTS

OF CYTOSKELETONS

FUNCTION

CONNECTS CELLS TOGETHER, OLDEST FORM OF JUNCTION,

FOUND IN ALL MULTICELLULAR

ORGANISMS

EXAMPLE

TISSUE WITH HIGH

MECHANICAL STRESS SUCH AS

THE SKIN

ADHESIVE JUNCTION(HEMIDESMOSOMES, FOCAL ADHESION)

STRUCTURE

INTEGRIN PROTEINS BINDS

CELL TO EXTRACELLULAR

MATRIX

FUNCTION

PROVIDE ATTACHMENT TO

A SUBSTRATE

EXAMPLE

INVOLVED IN CELL MOVEMENT AND IMPORTANT

DURING DEVELOPMENT

COMMUNICATING JUNCTION (GAP JUNCTION )

STRUCTURE

SIX TRANSMEMBRANE

CONNEXON /PANNEXIN PROTEINS

CREATING A PORE THAT CONNECTS

CELLS

FUNCTION

ALLOWS FOR PASSAGE OF

SMALL MOLECULES FROM CELLS TO CELL IN

A TISSUE

EXAMPLE

EXCITABLE TISSUE SUCH AS HEART MUSCLE

•PANNEXINS ARE PROTEIN FOUND IN INVERTEBRATES

•CONNEXONS ARE A PROTEIN IN VERTEBRATES

COMMUNICATING JUNCTION ( PLASMODESMATA)

STRUCTURE

CYTOPLASMIC CONNECTIONS

BETWEEN GAPS IN CONJOINING PLANTS CELL

WALLS

FUNCTION

COMMUNICATING JUNCTIONS

BETWEEN PLANT CELLS

EXAMPLE

PLANT TISSUE

•PLASMODESMATA IS CYTOPLASMIC CONNECTIONS THAT FORM ACROSS THE TOUCHING PLASMA MEMBRANES

ALL INFORMATION IN THIS POWER POINT CAN BE FOUND IN MGRAW HILL BIOLOGY 10TH

EDITION ON PAGES 83-85