Lecture 17 - GPCRs Flashcards
how many TM domains
7
Nterminus extracellular to recieve ligands
4 examples of ligands
glucagon
adrenaline
dopamine
histamine
2 ways GPCRs can be inactivated
phosph
internalisation of receptor
what proteins will allow exchange of GDP for GTP after lignad binds
GEFs
what hydrolysis of GTP
the effector which acts as GAP (GTPase activated protein)
which 2 subunits are anchored in memb
alpha and gamma
what type of effector is activated by the beta-gamma subunit complex
K+ ion channels
def of secondary messengers
rapidly produced diffusable signalling molecule that activates effector protein
what allow strong activation in short time
amplication of signal
ways to terminate signal
phosph
which could trigger endocytosis of receptor = recycled OR degraded
or could be -ve feedback loop
what enzyme converts ATP to cAMP
adenylyle cyclase
what deactivates cAMP
phophodiesterase
what molecule can cAMP activate
protein kinase A
how does cAMP activate protein kinase A
removes the 2 catalytic subunits from the regulaotry subunits (which are bound by disulphide bonds)
what AAs does protein kinase A act on
serine and threonine
what can PKA do when activated
translocate into nucleus
phosphorylate transc factors
that could up or downregulate gene transc
what happens when phospholipase C is activated
it cleaves PIP2 into IP3 and DAG (both of which are 2ndary messengers)
what type of phospholipase C activated by GPCRs
overall 3 types
and beta type is GPCR
what are the three types of inosityl phosphate
PI
PI(4)P
PI(4,5)P2
brackets jsut show where its phospho
