BIO-0046 Lecture Notes - Lecture 5: Protein Kinase A, Membrane Potential, Arrestin
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You identified a dn (dominant negative) mutation of a guanine nucleo-de. Gef promotes the exchange from gdp (off) -> gtp (on) So if you have no wt, it will be stuck at gdp. Intrinsic hydrolysis (gtpase) activity of ga can be accelerated by gaps. This can include the effector protein itself or other regulators o o o o o o o o. First ga was bound to gtp and liked its effector better. When it loses its affinity for effector because shape is wrong, it binds to gby. Gef: signal that causes gdp to be released and gtp to bind, turning it. G protein when off has gdp, gpcr changes the conformation. The gtpase activity of g protein turns it off, because it inverts gtp to. Gby is part of the complex, but it plays no role in removing gdp. Stress -> release of adrenaline -> b adrenergic receptor.