L10 GPCR Signalling Flashcards Preview

BMS242 Cell & Molecular > L10 GPCR Signalling > Flashcards

Flashcards in L10 GPCR Signalling Deck (43)
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1

Effectors of trimeric G proteins

enzymes

2

What do the effector enzymes of G proteins create

2nd messengers and ion channels

3

IP3

diffusible second messenger

4

IP3 function

controls calcium levels

5

Gqa receptors

a-adrenergic amines, Ach, various neurotransmitters

6

Gqa effectors

activate phospholipase Cb to produce IP3

7

What type of signalling is shared across many receptor families

signalling via lipid derived second messengers

8

Advantage of shared lipid signalling

cross talk and amplification

9

Lipid derived second messenger examples

PIP2, phosphatidylcholine, sphingomyelin

10

What targets membrane lipids

receptor regulated lipases

11

What are the two types of 2nd messengers derived from membrane lipids

i - water soluble, ii - hydrophobic molecules

12

Movement of water soluble lipid derived 2nd messengers

diffuse through the cytoplasm

13

Movement of hydrophobic lipid derived second messengers

remain in membrane

14

Function of lipid kinases

add phosphate groups to lipids

15

DAG

diacylglycerol

16

DAG structure

two fatty acid chains covalently bonded to a glycerol molecule through ester linkages

17

What is the more abundant lipid derived second messenger

Phosphatidylcholine

18

Example of hydrophobic 2nd messenger

DAG

19

Function of DAG

control signalling that occurs in PM

20

GPCR activation of PLC generates...

IP3 and DAG

21

What does specificity in signalling come from

selective expression and cellular localisation of signalling molecules

22

PH domain function

anchors parts of enzyme into PM

23

What is the PH domain important for

recognition

24

What is PKC regulated by

diaceylglycerol and calcium

25

Why is the location of a kinase important

it can only phosphorylate proteins near it

26

What are PKCs

ser/thr kinases

27

What is the PKC C1 domain activated by

DAG

28

What is the PKC C2 domain activated by

Ca2+

29

What is PMA

phorbol ester analogue of DAG

30

PMA function

activate PKCs

31

What does GFP tagged PKC imaging show

agonist dependent translocation to PM

32

What does PKC have built in

inhibitory peptide

33

Location of inhibitory peptide in PKC

when resting - folded into catalytic domain of kinase

34

What residues cannot be phosphorylated

alanine residues

35

Effect of phosphorylation

switches ON/OFF a function

36

What does DAG binding to PKC cause

dissociation of intramolecular pseudosubstrate domain from active site

37

What can phosphorylation of receptors contribute to

desensitisation

38

Function of munc13

controls docking of secretory vesicles at PM

39

What recruits munc13

activation of GqPCRs and synthesis of DAG in PM

40

What causes Lowe syndrome

mutations in OCRL

41

How is a large chemical gradient for calcium created

proteins in lumen of ER bind up Ca2+

42

How is calcium influx into the cytosol regulated in the PM

voltage and ligand gated channels

43

What is STIM

protein in ER that senses calcium