PHSI3009 Lecture Notes - Lecture 7: Inositol Trisphosphate Receptor, Calsequestrin, Not Exactly C

• School: University of Sydney
• Department: Physiology
• Course: PHSI3009
• Professor: any

Document Summary

Ca2+ signalling toolkit: receptors, ca2+ channels, ca2+ pumps, ca2+ sensors, ca2+ sensitive cellular processes (insulin secretion, nts release, actin remodelling) Ca2+ as a signal: can be from outside/inside (rapidly mobilized, ca2+ shut-off pathways (rapidly removed or sequestered, voltage-gated ca2+ channels inactivate. Ip3 rapidly dephosphorylated: ca2+ rapidly pumped out/taken up. Ca2+ channels: voltage gated (n, t and l, store operated (crac)- orai, non-selective cation channels (trps)- stretch sensitive, capsacin etc , ligand gated (e. g. p2x-atp) Er/sr main intracellular stores: bound to calsequestrin (sr, ryanodine and ip3 receptors (ns channels!, lysosomes also important sources of ca2, mito and nucleus not so critical. Main transporters: pmca plasma membrane ca2+-atpase, na-ca (nxc) exchanger (v important muscle, serca sarco-endoplasmic reticulum ca-atpase (up to 80% of membrane protein in er!) Calcium uptake and deprivation: na/ca exchanger on plasma membrane, ca pump on er membrane, ca binding molecules, ca pump om mitochondria.