12. Cytosolic side of receptor is the binding site for heterotrimeric g proteims, which contains a loop between strands 5 and 6 and ligand binding domain is between 6 and 7. – extracellular
13. When ligand binds to it, it exposes an activation site (binding site) for heterotrimeric g proteins, which is linked to the membrane (meristic acid that links protein to membrane) and when exposed, interacts with HTGP
15. Once the alpha subunit is removed, the enzyme is inactive. When the alpha subunit is bound to GDP, it no longer associates with the enzyme and it exposes binding sites for B/G subunit, so they can all come together.
30. Stimulates the function of adenylyl cyclase (a.k.a. adenylate cyclase) – designation for alpha subunit of this g protein.
31. Referred to as alpha-s, when bound to GTP, moves through membrane, attaches to adenylyl cyclase and turns it on. Therefore, that leads to an increase in cAMP in the cell
36. Adenylyl cyclase removes a pyrophosphate (2) from ATP and make cAMP, a favorable reaction by breaking the phospoanhydride bonds holding the Pi on to the ATP
48. Heterotrimeric (as are all) that does different things in different cells, where in some cases the B/G is only active, but sometimes both A and B/G participate in target activation
49. Beta gamma turns on or opens up K+ channels in the PM allowng K+ to rush out of cell
50. When A and B/G are both active, Phospholipase c-beta is turned on
51. PLCB or PLCG both cleave PIP2 (generating DAG that remains attached to membrane and releases IP3 into the cytosol to bind to IP3 receptors in the ER) in the membrane
72. cAMP binds to a kinase, called protein Kinase A, which sits in cytosol in inactive state until bound by cAMP. Similar to cGMP. PKG and PKA both have a structure so they have regulatory sites that can be bound by an intracellular signaling protein
73. when they are bound, open up and release catalytic site that does the phosphorylating.
77. Once PKA or PKG is activated we have catalytic sites that are turned on ready for phosphorylation, and both target serine and threonine as target proteins.
78. Recognize the amino acids on either side of the phosphorylated threonine/serine really.
92. Also for cAMP regulation: active phosphodiesterase will break down cyclic AMP to AMP, and inactivation will cause cAMP to stick around to active more PKA. Synthesis and degredation is regulatable.
107. G protein linked receptor that binds ligand will have a heterotrimeric g proteinactive
108. Activated alpha will move through membrane and activate PLCB that exposes cleavage site that can cleave phosphoinositol bisphosphosphate into DAG and IP3 signaling molecule
109. As IP3 moves to receptors on intracellular Ca2+ storage sites, it binds to IP3 receptors and it itself opens up and allow calcium to move to the cytosol. (it is an ion channel, the receptor)
110. DAG and Ca2+ will activate PKC inside the cell.
111. PKC enzyme phosphorylates serine and threonine is activated by DAG in phospholipid bilayer, binding of PS (phosphatidalserine, inserted in PM and flipped to inner leaflet) in the lipid bilayer and the binding of calcium that is required for activation of PKC
120. Calmodulin has a complex carboxy and amino termini. Within globular ends, there are two binding sites for calcium so four calcium molecules are bound by calmodulin in cytoplasm and is then activated
121. Once activated can form kinase, which can wrap itself around a phosphorylating enzyme and stays attached to it. Ca calmodulin complex is PART OF THE KINASE SO IT CANNOT FUNCTION WITHOUT THE ENZYME