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
