Receptors and signal transduction IV Flashcards
Where are M2 and M4 muscarinic autoreceptors found?
Nerve terminal
Role of M2 and M4 muscarinic receptors?
Regulation of transmitter release
Where is the M4 muscarinic receptor v important?
Striatum and basal ganglia
Role of M4 class of muscarinic receptor in striatum and basal ganglia?
Regulation of dopamine release
What does the M2 receptor regulate?
ACh release
Most widely expressed muscarinic receptor?
M1
What are drugs against muscarinic receptors used to treat?
COPD, asthma, overactive bladder
Nicotinic subunit structure?
Cys loop, four transmembrane domains
Which transmembrane domain of the nicotinic subunit is responsible for the ion channel?
M2
How many subunits make up a nicotinic ACh receptor?
5–> pentameric
Where are a lot of the ACh receptors found?
Muscle
What are alpha7 nicotinic receptors permeable to?
Ca2+
Where are alpha7 nicotinic receptors found?
Forebrain
What are alpha7 nicotinic receptors important in?
Regulation of cognition and executive function
How many ACh binding sites does alpha7 nicotinic receptors have?
5
Principle ACh receptor makeup (other than alpha7 nicotinic receptors)
Alpha 4, beta 2 w/ 2 ACh binding sites
GABAb receptor structure?
Dimers
Where are GABAb receptors found?
Pre n
Role of GABAb receptor?
Regulate transmitter release
How do GABAb receptors regulate transmitter release?
Opek K+ channels, inhibiting Ca2+ channels
Done by beta gamma subunit from the g protein
GABAa subunit structure?
4 transmembrane domains, cys loop, second transmembrane domain is pore forming
Usually two alpha, two beta then another (gamma etc)
GABAa structure?
pentamer (5 subunits)
What are GABAa receptors permeable to?
Cl-
How many GABA binding sites do GABAa receptors have?
2, between the alpha and beta subunits
