GPCRs

Question 1

how many TMDs in GPCRs

Answer 1

7

Question 2

G protein activation

Answer 2

GDP unbinds
GTP binds
A dissociates from Bg
GTP degraded
GDP rebinds

Question 3

What does NHERF scaffold

Answer 3

PTHR to make it Gq from Gs
With Gq, TRPC, PLPC and PKC

Question 4

Which ion channels do AKAPs regulate

Answer 4

M type KCNQ2 with PKC and PP2B
TRPV1 with PKA and PKC

Question 5

What trafficking does AKAPs regulate

Answer 5

Both with B2AR, AC and PKA
AMPAR with SAP97, PSD95
L type Cav1.2

Question 6

GPCR termination

Answer 6

GRK attracted to CTD
Phosphorylates CTD
Arrestin binds
Arrestin interacts with Clathrin and AP2
Forms endosome

Question 7

How to rescue GPCR function

Answer 7

GRK/arrestin inhibition- prolong signalling

Question 8

What does GRK2 inhibitor Takeda 1021 do

Answer 8

Reverse Mu-OR desensitisation - longer analgesia

Question 9

What does endosomal GPCR/arrestin signalling activate

Answer 9

Raf1, ERK, MAPK
Src
both induce Growth factor responses

Question 10

Biased Mu-OR agonist

Answer 10

TRV130 only activates Gi protein

Question 11

Biased agonism in angiotensin 2 type 1 R

Answer 11

B arrestin only signal for cardiac contraction
Remove hypertension from Gq

Question 12

What does GRK2 do

Answer 12

increase G protein desensitisation

Question 13

What does GRK6 do

Answer 13

increase ERK activation

Question 14

Effect of arresting binding to V2R

Answer 14

increase ERK

Question 15

Effect of arresting binding to BK2R

Answer 15

reduce ERK

Question 16

Two steps of arrestin docking?

Answer 16

Bind to CTD
Active GPCR- insert finger loop into GPCR