bio46 cell signaling from week 11 comprehension ws

proximity tagging

compared to Co-IP, tells you if two proteins directly interact; by encoding half of GFP into each protein and looking at fluorescence; fluorescence localization and duration in certain areas → where and for how long proteins interact directly

epistasis analysis

knocking out inhibitors to see downstream signaling effects

G-coupled signaling overview

extracellular signal causes conformational change in GPCR; GPCR exchanges GDP for GTP on G-alpha, causing G-alpha to separate from G-beta/omega; G-alpha involved w adenylyl cyclase to produce cAMP → kinase A or lipid signaling pathway; G-beta/omega interact with ion channels when released

protein kinase A structure

2 regulatory subunits, each with two cAMP sites; 2 catalytic subunits w ATP site, substrate binding site, and regulatory unit binding site

PKA production

translated in cytosol; 2 genes encode for different subunits; subcellular localization regulated bc diffus-ability changes depending if regulatory elements are bound or not so fast and slow signaling effects

RTK

receptors tyrosine kinases; when brought tgt, phosphorylate each other, then activate intracellular signaling proteins, which then activate Ras proteins via GDP → GTP, which then activate kinase cascade/amplification

CREB

cAMP response element binding protein; transcription factor