Signal Transduction - GPCR

Question 1

What receptor is shown?

Answer 1

GPCR

Question 2

Can the effector of a GPCR be an ion channel?

Answer 2

Yes

Question 3

Where does the receptor exist in a GPCR?

Answer 3

Plasma membrane

Question 4

What 2 receptors can the G protein activate?

Answer 4

Enzyme or ion channel

Question 5

What are seconds messengers?

Answer 5

Transfer a signal from the membrane to the rest of the cell

After (receptor activation)

soluble products

intracellular site of action

amplify the response

Question 6

When the ligand activates the GPCR, is the signal continuous?

Answer 6

Yes

Question 7

What is the chain of events in the GPCR?

Answer 7

Question 8

What do second messengers do?

Answer 8

Question 9

What are 4 examples of effectors in a GPCR?

Answer 9

Question 10

What are examples of GPCR? (receptor)

Answer 10

Question 11

What is the second messenger of adenylate cyclase effector?

Answer 11

cAMP

Question 12

What is reaction of adenylate cyclase to camp?

Answer 12

ATP to CAMP + PPi

Question 13

Can adenylate cyclase link inhibitory and stimulatory receptors?

Answer 13

Yes

regulated by Gs and Gi

Question 14

What are the stimulating receptors adenylate cyclase?

Answer 14

Beta adrenergic

ACTH

Question 15

What are the inhibitory receptors of adenylate cyclase?

Answer 15

Alpha 2 receptors

Muscarunic

Opiate

GABA b

Question 16

What does camp activate?

Answer 16

PKA

Question 17

What does the inhibitory GPCR cause? (Gi, no cAMP)

Answer 17

M2, Ach R = Decreased HR

Alpha2:

Inhibitory neurotransmitter release

Contraction in smooth muscle

inhibition of insulin

Question 18

What is the effect of activating the inhibitory opioid GPCR? (no cAMP)

Answer 18

SEDATION…

Question 19

What are the sites if action of opioid analgesics?

Answer 19

Peripheral

Spinal

Supraspinal (medulla, thalamus, cortex)

Question 20

What is the best known opioid anagesic?

Answer 20

Morphine

Question 21

What is the most commonly prescribed opioid analgesic?

Answer 21

Codeine

Question 22

What are naturally occurring opioids?

Answer 22

Endorphins

Question 23

What are compounds related to opioids?

Answer 23

Methadone

Dimorphine (heroine)

Fentanyl

Question 24

What G protein activates PLC?

Answer 24

Gq

Question 25

What are the second messenger of PLC?

Answer 25

IP3
DAG

Question 26

What is the pathway of PLC (effector) in the GPCR?

Answer 26

Question 27

What can GPCR also be called?

Answer 27

metabotropic receptors

Question 28

What are the second messengers of PLC?

Answer 28

IP3

DAG

Question 29

What activates the Gi (regulates adenylate cyclases)?

Answer 29

opioid agonists

Question 30

What does increased cAMP in the cell cause? (activate PKA)

Answer 30

Question 31

What are the contradictory effects of giving someone adrenaline?

Answer 31

Beta2 receptor increases glycogen and fat metabolism in liver, fat and muscle cells

Beta1 receptor increases activity of voltage activated calcium channels in heart cells

Question 32

Opioids inhibit AC and there for decreased cAMP and PKA levels, what is the effect of this?

Answer 32

PKA does not phosphorylate K+ channel or Ca2+ channel

this open the K+ and closes the Ca2+

hyperpolarisation

inhibition of AP

Question 33

What receptor do opioid analgesics use?

Answer 33

mu receptors mainly for analgesic effects

3 types: mu, kappa, delta

Question 34

What type of effector is PLC?

Answer 34

membrane bound enzyme

Question 35

What does IP3 do? (PLC pathway)

Answer 35

increase in intracellular Ca2+

Question 36

What does DAG do? (PLC pathway)

Answer 36

activation of PKC

Question 37

IP3 increases Ca2+ in the cell, what does this result in?

Answer 37

Question 38

DAG activates PKC, what does this result in?

Answer 38