Flashcards in L9 - GPCRs Deck (50)
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1
Which is the largest receptor family
GPCRs
2
Structural features of GPCRs
7 transmembrane spanning domains
3
Alpha helix 3 in GPCRs
always orientated towards centre of structure
4
Function of alpha helix 3 in GPCRs
contributes to binding site
5
What connects TM domains
Intracellular and extracellular loops
6
N terminus location GPCRs
Points out of the cell - extracellular
7
C terminus function in GPCRs
regulation of receptor function
8
What do receptor families share
one or more homologous domains
9
States of GPCRs
resting and active
10
Which regions open up the GPCR
TM5 and TM6
11
TM3 function in GPCR
central location, crucial for transduction of ligand binding
12
What domains does TM3 send the transduction to
TM5 and TM6
13
What else can contribute to ligand binding
Extracellular N terminus
14
PAR receptor
GPCR for thrombin
15
What activates PAR receptors
proteinases
16
PAR receptor function
blood clotting and wound healing
17
Thrombin
protease (enzyme)
18
Thrombin function
cleaves amino terminus of receptor
19
Effect of cleaving amino terminus of PAR receptor
activates receptor
20
What two receptors are involved in blood clotting
thrombin receptor and ADP
21
Blood thinners interfere with which receptors
thrombin receptor and ADP
22
Which patients require blood thinners
patients at risk of stroke or clotting
23
ADP receptor type
purinergic
24
Allosteric modulator
molecules that act away from ligand binding site
25
Impact of allosteric modulator
may impact receptor function
26
Describe the resting GPCR
three inactive components
27
How is the resting GPCR activated
ligand binding and exchange of GDP for GTP
28
End result of active GPCR
three separate active components
29
inactive alpha subunit Gprotein characteristics
alpha subunit has high affinity for GDP
30
GEF
guanine exchange factor
31
GEF function
causes GDP to fall off and GTP to come on
32
RGS
regulators of G protein signalling
33
How is receptor signalling system adapted
feedback
34
Olfactory receptors activation
transduced through same trimeric G protein
35
What do RGS proteins stimulate
GTPase activity
36
What is duration of signalled by activated trimeric G protein regulated by
rate of GDP hydrolysis by Ga
37
What do G proteins control production of
second messengers, and ion channels
38
What are effectors of trimeric G proteins
enzymes
39
What do G proteins effectors (enzymes) control levels of
second messengers
40
What is local concentration fo 2nd messengers determined by
rate of production, rate of diffusion and rate of removal
41
What regulates cAMP production
adenylyl cyclase
42
What removes cAMP
phosphodiesterase
43
What does activated adenylyl cyclase catalyse
ATP into cAMP
44
How many isoforms of adenylate cyclase are there
10
45
What activates adenylate cyclase
Gas
46
What inhibits adenylyl cyclase
Gai
47
What does B2 adreno-receptor regulate
metabolism in liver and skeletal muscle
48
What does stimulation of cAMP and adenylate cyclase activate
PKA
49
PKA function in metabolism
sets up signalling cascade that phosphorylates enzymes controlling glycogen metabolism
50
