BIO 3153 Lecture Notes - Lecture 18: Adenylyl Cyclase, G Protein–Coupled Receptor, Endocytosis
Document Summary
Lecture 18 cell communication/signaling ii: g-protein coupled receptors. Receptors: largest family of cell-surface receptors, g protein is tethered protein on inside of cell, g-protein-coupled or metabotropic receptors, mediate responses of ligands (ex. Nt, hormones), important in sensory systems: interact with gtp binding proteins, contains 7 membrane helices, n-terminus 3 extracellular loops form binding site, c-terminus 3 intracellular loops bind to g proteins, ex. Process g protein activation (1), target protein activation (2), g protein. Signaling pathways: 2 pathways for g proteins *involve second messengers ac, pc. 2) gpcr activates g protein, activates phospholipase c that can either form ip3 or dag. G-protein regulation of cng ion channels: regulation of cng by gpcrs important for sensory transduction, gprcs mediate communication, stimulating g olfactory and g transducing change cyclic nucleotide concentrations, effects of pka on gene transcription. Long term effects of pka activation can cause protein production that changes the cell over time. Upregulation of enzymes or hormones (ex. somatostatin)