Voltage Gated Ca Channels

Question 1

What is the primary subunit that forms the ion-conducting pore of voltage-gated Ca²⁺ channels?

Answer 1

A1

Question 2

What are the auxiliary subunits

Answer 2

B
A2o
Y

Question 3

What role do β subunits play in voltage-gated Ca²⁺ channels?

Answer 3

Anchor

Question 4

Which voltage-gated Ca²⁺ channel subunit is primarily responsible for the pore’s ion selectivity?

Answer 4

A1

Question 5

What type of Ca channel is CaV1.1-1.4

Answer 5

L-type

Question 6

Which type of voltage-gated Ca²⁺ channel is associated with lower activation thresholds and faster kinetics?

Answer 6

T type Ca channels CaV3.1-3.3

Question 7

What type of Ca channel is associated with high voltages activated channels and log lasting currents

Answer 7

L type

Question 8

Which type of calcium channels are responsible for muscle contraction and hormone secretion

Answer 8

L type

Question 9

Which CaV channel subtype is primarily involved in neurotransmitter release?

Answer 9

P/Q type CaV2.1

Question 10

What role do N-type CaV2.2 channels play in the nervous system?

Answer 10

Mediated neurotransmitter release at pre-synaptic terminal

Question 11

What type of channel is CaV 2.2

Answer 11

N type

Question 12

Which CaV channel subtype is known for having a low activation threshold and fast inactivation?

Answer 12

T type CaV3.1-3.3

Question 13

What is the primary function of CaV1.2 channels?

Answer 13

Excitation contraction coupling

Question 14

What type of channels are low voltage activated channels with transient fast inactivating currents

Answer 14

T type CaV3.1-3.3

Question 15

Which kinases are primarily involved in the phosphorylation of CaV channels?

Answer 15

PKA and PKC

Question 16

How does phosphorylation by PKA affect CaV channels?

Answer 16

Enhances Ca²⁺ currents by increasing channel opening

Question 17

What effect does PKC phosphorylation have on CaV channels?

Answer 17

Enhance or inhibit channel activity

Question 18

Effect of Gβγ subunits on CaV channels

Answer 18

Inhibit them decreasing Ca entry

Question 19

What subunit does βγ interact with to cause a conformational change

Answer 19

A1

Question 20

How does the activation of Gq-coupled receptors affect CaV channels?

Answer 20

increased intracellular calcium levels, which can enhance the activity of CaV channels via the phospholipase C (PLC)

Question 21

What is the effect of Gi-coupled receptor activation on CaV channels?

Answer 21

inhibits CaV channels through the βγ subunit, decreasing calcium influx

Question 22

How does calcium-induced calcium release (CICR) relate to CaV channels?

Answer 22

Activation of CaV channels allows calcium entry, which can trigger further release of calcium from the endoplasmic reticulum via ryanodine receptors, amplifying the intracellular calcium signal.

Question 23

What are channelopathies?

Answer 23

Mutations in ion channel genes

Question 24

Name a channelopathy associated with mutations in the CaV1.1 channel.

Answer 24

Hyperkalemic periodic paralysis

Question 25

What condition is caused by mutations in the CaV1.2 channel?

Answer 25

Timothy syndrome

Question 26

What condition is due to mutation in CaV2.1

Answer 26

Episodic axtasia type 2

Question 27

Name a channelopathy linked to CaV2.2 (N-type) channels.

Answer 27

LEMs

Question 28

What are CaV3.1 channels associated with in terms of clinical conditions?

Answer 28

Absent seizures

Question 29

Which calcium channel mutation is implicated in Familial Hemiplegic Migraine (FHM)?

Answer 29

CaV2.1