Upload
scot-carr
View
224
Download
2
Tags:
Embed Size (px)
Citation preview
Lecture 05 – Extracellular Signal Receptors III
BIOL 5190/6190 Cellular & Molecular Singal TransductionPrepared by Bob Locy
Last modified -13F
Ion channel receptors
Voltage Operated Channel
• Multisubunit – a1, a2, b, d, & g
• Calcium channel – in PM
• 1a – contains voltage sensor
• a1 – also contains drug binding sites
• Large cytosolic loop, links to synaptic vessicle and/or ryanodine receptors
• a2 – extracellular, regulatory, glycosylation
• d – transmembrane region
• b – intracellular and functions to mediate intracellular effects in different cell types
Ion channel receptors
Detailed structure• A1 has 4 repeat domains
(I-IV) each with 6 MSDs• MSD6 of each domain
makes the pore• b has 4 alpha helices, but
no MSDs• a2 and d (single MSD)
associate via disulfide • g has 4 MSDs• Regulation by protein
kinase A (AKAP18) phosphorylation.
Ion channel receptors
• 1.2 L-type channel (shown) differs in regulation from 1.1 L-type channel• PKC• Calumodulin (CAM)• G-protein
regulation of PP2A
Ion channel receptors
• IP3 Receptor animation