Lecture 4 Flashcards Preview

106: Receptors and Cellular signalling > Lecture 4 > Flashcards

Flashcards in Lecture 4 Deck (13):
1

What are the largest family of receptors and how much of the human genome do they account for?

GPCR
2% of the human genome

2

What are the two important features that all tyrosine kinase receptors have?

- all have extracellular binding domain
- inside the cell there's a kinase domain

3

what is an example of class 1

EGF

4

what is an example of class 2

insulin receptors

5

what is an example of class 3

FGF

6

what does insulin do?

stimulates the uptake of glucose in the muscle cells when blood glucose level are high

7

what kind of receptor is the insulin receptor

a dimer

8

describe the basic structure of insulin

large, 2 chain hormone
A and B chain

9

true or false; beta subunit of insulin receptor spans the cell membrane and is inside the cell

true

10

describe the steps of how insulin receptor works?

1.) insulin binds to the alpha subunit
2.) this triggers a conformational change in the receptor activating the kinase domain of the B-receptor
3.) the activated kinase domain, will undergo auto-phosphorylation of the tyrosine domains
4.) receptor then phosphorylates tyrosine residues on target proteins
5.) these are known as IRS (insulin receptor substrates); considered as second messengers

11

how does insulin acting in the muscle stimulate glucose uptake

GLUT-4 is moved to the cell surface (translocation)

12

what are the similarities between RTKs and GPCRs

- both types of receptors are activated by hormones
- both types of receptor span the membrane and undergo a conformational change when the hormone binds
- second messengers are involved in the signalling process for both types of receptors
- phosphorylation events are important

13

What are the differences between GPCRs and RTKs

- RTK contains kinases as part of receptor but GPCRs do not
- GPCRs use G protein but RTKs do not
- the structures of the receptors are different