Cellular Receptors Flashcards
Which hormones can activate intracellular receptors?
The lipid soluble steroid and thyroid hormones - the hormone-receptor complex binds directly to DNA
What are two second messengers controlled by G-protein linked receptors?
cAMP and Ca2+
What enzyme activated following G-protein linked receptor binding causes ATP to be converted to cAMP?
Adenylate cyclase
What does cAMP do?
Activates protein kinases which open ion channels or activate enzymes
What enzyme inactivates cAMP?
Phosphodiesterase
Which compounds bind to G-proteins to activate cAMP?
(Nor)epinephrine(beta) Calcitonin Anterior pituitary hormones (TSH, LH, FSH, ACTH) PTH ADH Glucagon
Which compounds bind to G-proteins to inactivate cAMP?
(Nor)epinephrine (alpha 2)
What enzyme produces IP3 and DAG?
Phospholipase C1
What binds to ion channels to open them?
G protein + GTP
What does IP3 do?
Releases Ca2+ from intracellular stores
What does DAG do?
Activates protein kinases
What enzyme does Ca2+ directly bind to?
Calmodulin
What function can only be performed by neurotransmitters?
Opening of ion linked channels
What compounds can bind to g-protein linked receptors to increase intracellular Ca2+?
(Nor)epinephrine(alpha 1)
Oxytocin
HRH
What kinase is targeted by catalytic receptor proteins?
Tyrosine specific protein kinases
