signal trans 3 part 2 Flashcards
GPCR has – transmembrane alpha helixes
7
tf the N terminal is on ext side and C terminal in on the int. side in GPCR.
T
glycosylation ; phosphorylation in GPCR
N; C terminal in GPRC
rhodopsin recptor
GPCR
Largest subunit in gpcr
alpha
phillic to phobic on gpcr
alpha; betay on gpcr
Guanine nucleotide-binding site (GDP, GTP) and GTPase activity
alpha subunit of GPCR
GPCR portion that interacs with effector protein
alpha subunit
BY unit of GPCR
cov attach to membrane with some int. with effector protein
after ligand bidns GPCR —- —–,
GDP/GTP exchange causes—– with —– to dissociate
conf change
alpha subunit with GTP
(GPCR)
seconary enzyme in GPCR
will bing alpha subunit with GTP
and intrinsic GTPase activation cause Hydrolysis of GTP to GDP and release of alpha GDP

major mechanism of desensitization of GPCR
Receptor phosphorylation by protein kinases
Protein kinase A (PKA); receptor
GPCR-specific protein kinases (GRKs); receptor
+/- ligand GPCR-specific
+ ligand
Extracellular enzymes —– or —- many of the small ligands.
Extracellular enzymes metabolize or inactivate many of the small ligands.
GPCR inact

Extracellular enzymes metabolize or inactivate many of the small ligands.

Receptor phosphorylation by protein kinases
GPCR termination
—— —— endocytosis accounts for some desensitization
Receptor-mediated endocytosis accounts for some desensitization
GPCR inact.
Effect of EToh on GABA bidning site
Causes membrane potential to become more negative
Increases GABA’s suppression of neural activity
Increases dopamine release

Caffeinated Alcohol Drinks
—– Binds to allosteric binding site on GABA-bound receptor
ethanol
TF in : Caffeinated Alcohol Drinks
EToh bidning to GABA receptor keeps it closed
F keeps it open
GABA Ligand-Gated Ion Channel
Anion-Selective (Inhibitory)
Adenosine G-Protein-Coupled Receptor thru caffiene stimulant
① Blocks adenosine binding site (antagonist)
Normally Adenosine G-Protein-Coupled Receptor
Suppresses neural activity; increases blood flow




