PHAR232 - receptors and targets

Question 1

What are receptor tyrosine kinases (RTKs)?

Answer 1

A kinase putting a phosphate on tyrosine

Question 2

What’s another name for receptor tyrosine kinases (RTKs)?

Answer 2

Kinase linked receptors

Question 3

How many estimated genes have been associated with RTKs?

Answer 3

59 genes

Question 4

Quick review

Answer 4

Question 5

Question 6

What does a kinase do?

Answer 6

Puts a phosphate on
(phosphorylation = activation)

Question 7

What does a phosphatase do?

Answer 7

Takes phosphates off
(dephosphorylation = deactivation)

Question 8

What is dimerisation?

Answer 8

two molecules come together to form a dimer, a complex consisting of two subunits.

Question 9

What is growth factor receptor signalling especially goal orientated towards?

Answer 9

Gene transcription

Question 10

Answer 10

Question 11

What is the primary goal of the nuclear receptors?

Answer 11

Alter gene transcription

• bind directly to DNA to trigger transcription of designated genes

Question 12

What is another name for DNA binding domain?

Answer 12

Zinc fingers

Question 13

Question 14

Activation of gene tranription occurs in what 2 phases?

Answer 14

• Primary response (within 30 mins)
• Secondary response (utilises primary genes and takes longer)

Question 15

What are 2 non ligand-gated ion channels?

Answer 15

• Voltage-gated
• Small cation channels

Question 16

Answer 16

Question 17

Answer 17

Question 18

What do false-substrates do?

Answer 18

Try to out-compete normal substrates

Question 19

What are pro-drugs?

Answer 19

they become a blocker once acted upon by enzyme to be blocked

Question 20

What type of enzyme inhibitor is aspirin?

Answer 20

Irreversible inhibitor
- protein target must be destroyed in order to remove the drug
(like irreversible receptor antagonist)

Question 21

What is a competitive enzyme inhibitor?

Answer 21

Binds to the same site as normal substrate but CANNOT be catalysed
e.g. ACE inhibitors e.g. captopril

Question 22

Answer 22

Question 23

Question 24

Define receptor desensitisation

Answer 24

Loss of sensitivity of receptor continually stimulated by agonist e.g. insulin resistance

Question 25

Question 26

How do receptors predominantly undergo desensitisation?

Answer 26

• ## PHOSPHORYLATION OF RECEPTORS

Question 27

What is the protein that removes a receptor from the membrane for cellular desensitization?

Answer 27

Arrestin

Question 28

What protein does homologous pathway of desensitization utilise?

Answer 28

Arrestin (it’s ARRESTING the molecule = no longer working)

Question 29

What does is the end result of heterologous receptor desensitation?

Answer 29

Reduced G-protein coupling

Question 30

LEARN - DESENSITIZATION & RECEPTOR TRAFFICKING - draw it out

Answer 30

Question 31

Question 32

Is caffeine an antagonist or agonist of adenosine receptors?

Answer 32

antagonist

Question 33