Konorev DSA: Drug Targets

Question 1

What does Gs do?

Answer 1

-activates all isoform of AC and Src tyrosine kinase

Question 2

What doe Gi do?

Answer 2

-inhibits AC but activates tyrosine kinase Src

Question 3

What does Gq do?

Answer 3

-activates PLC

Question 4

What happens when we activate a GABA-A receptor?

Answer 4

-inward flux of Cl-….. hyperpolarization

Question 5

NAch receptor activation

Answer 5

• binds to alpha receptors

- inward Na flux… depolarization

Question 6

What is a JAK receptor?

Answer 6

-receptor coupled to cytosolic protein kinase

Question 7

How is JAK receptor different from RTK?

Answer 7

-RTK has intrinsic enzymatic activity

Question 8

What happens to a GPCR after it gets activated too much?

Answer 8

• gets phosphorylated then B arrestin latches on…… gets internalized (desensitization).
• it reverses back pretty quickly once the ligand leaves

Question 9

What is an inert binding site?

Answer 9

-the drug binds to it but doesn’t change its function

Question 10

What do we call the molecule that binds to a receptor?

Answer 10

-the ligand

Question 11

What is the specific DNA sequence that transcription factors bind to called?

Answer 11

-the response element!

Question 12

What does DAG activate?

Answer 12

-PKC

Question 13

True or False, GTP hydrolysis by Beta gamma subunit will terminate the activity of a GPCR.

Answer 13

• False

- GTPase activity is only present in the alpha subunit!

Question 14

When Active, Gaq results in the increased level of PIP2… is that correct?

Answer 14

• no
• it makes PIP2 turn into IP3 via the activation of PLC!
• so , the concentration of PIP2 will actually decrease

Question 15

When a boy is using the a B2 adrenergic agonist and it stops working as good, what is the first thing that is happening to the receptor?

Answer 15

• it gets “P”ed first
• then B arrestin binds to it
• then it binds to the coated pit
• gets internalized

Question 16

What kinds of receptors are growth factors normally?

Answer 16

• RTKs

- so, if there is “GF” anywhere in the name, it’s probs an RTK

Question 17

What do proteins that contains a SRC homology 2 domain bind to?

Answer 17

• proteins that have a phosphotyrosyl residue
• SH2 binds to P’ed RTK
• SH3 binds SH2… then SOS (which is a GEF) binds to SH3

Question 18

What is Ras?

Answer 18

-a monomeric GPTase

Question 19

What is Grb2?

Answer 19

-an adaptor ptn

Question 20

What is Sos?

Answer 20

a GEF

Question 21

What chemical messenger passes through the plasma membrane of cells and has receptor molecules in the cytoplasm?

Answer 21

-Testosterone apparently

Question 22

What is phosphorylated as a result of binding of a cytokine like IL-2 to its receptor?

Answer 22

• STAT protein
• JAK/STAT signaling
• STAT comes over when receptor is activated… magic happens

Question 23

do voltage gated channels open and close in response to a chemical signal?

Answer 23

-no! VOLTAGE

Question 24

Binding of a NT to which type of receptor directly leads to a change in distribution of ions between extra and intracellular compartments?

Answer 24

-Ligand-gated ion channels

Question 25

permeability of what ion is incrased as a result of the activation of a nicotinic receptor?

Answer 25

-mostly Na+