GPCR 2 and calcium homeostasis Flashcards
Name 4 effector enzymes and what reactions they catalyse.
adenylyl cyclase ATP==> cAMP
phospholipase C PIP2==> DAG+ IP3
phosphoinositide 3- kinase PIP2==>PIP3
cGMP phosphodiesterase cGMP==>5’- GMP
Name two ion channels that GPCRs act on.
voltage operated ca channels (VOCC)
G-protein regulated inwardly rectifying K+ channels (GIRKs)
Name the adenylyl cyclase activating subunit
alpha s
Name three receptors that activate AC
beta adrenoreceptor
D1- dopamine receptor
H1- histamine receptor
What does cAMP activate?
PKA
cyclic AMP dependent protein kinase A
Name the adenylyl cyclase inhibitory subunit
alpha i
Name three receptors that inhibit AC.
alpha 2 adreno receptor
D2 dopamine receptor
u opioid receptor
name three receptors that activate phospholipase C
alpha 1 adrenorecpetor
m1 muscarinic receptor
h1 histamine receptor
Name the phospholipase C activating subunit
alpha q
What does the activation of phospholipase C cause
pip2 to DAG and ip3
ip3 to ca on sr/er released ca in to cytoplasm
Explain signal amplification
allows small extracellular signals to elicit significant changes in cellular behaviour
Explain how heart inotropy can be increased
adrenaline + noradrenaline to beta 1 receptor
g alpha s to ac to camp to pka
vocc phosphorylated
Ca influx
How is vasoconstriction caused by GPCR’s?
noradrenaline to alpha 1 to vasocontriction via Gq-phospholipase c pathway
How is bronchoconstriction caused by GPCR’s?
ACh to M3 to bronchoconstriction via Gq-phospholipase C pathway
How can modulation of NS release via GPCR’s allow pain relief?
morphine to u-opioid receptor g-protein activated
beta gamma subunit inhibits VOCC
prevent NT release
