lecture 24 redone

Question 1

PH domain
proteins with PH domain bind to

Answer 1

phosphorylated inositol phospholipis in the plasma membrane (localises signallng)

Question 2

PTB domain

Answer 2

binds phosphotyrosine (P-Y) residues

Question 3

SH2 domain
2 domain binds phosphotyrosine residues surrounded by unique proetin sequences

Question 4

SH3 binds to specfically to proline rich regions

Question 5

insulin receptor is a tetrameric tyrosine kinase receptor

Answer 5

2alpha , 2 beta , alpha at top so binds

Question 6

the IR is expressed as two isoforns

Answer 6

isoforn A and B

Question 7

beta subunit has tyrosin kinase redisues meaning it can

Answer 7

phosphorylate tyrosine when activated

Question 8

Shc - SH2 containing apapter protein
Shc has PTB and SH2 domain
shc can bind to insulin receptor, when they bind tyrosine is phosphorylates uncoveing a binding site for binding SH3 domain

Answer 8

e.g Grb2 from SH3 domain binds to Shc

Question 9

IRS = insulin receptor substrate (adapter protein)
IRS1,2,3,4 contains a

Answer 9

PH and PTB domain

Question 10

PH and PTB domain enable binding to phosphorylates insulin receptor, after binding the IRS becomes phosphorylated on tyrosines by

Answer 10

IR tyrosine kinase activtity

Question 11

IRS has wq potential tyrosine phosphorylation sites

Answer 11

making it a dokcing protein for proteins with SH2 domains

Question 12

PI3 kinase, Grb2 and SHP2

Answer 12

can bind to IRS as the have SH2 domains

Question 13

insulin receptor is bound to by IRS which is bound to by Shc via the Grb2, interacts with

Answer 13

SOS when bound

Question 14

SOS acts as a GDP/GTP exchange factor
ras ia inactive when bound to GDP ras is activtated when its exchanged for GTP. Ras GTP activates

Answer 14

raf

Question 15

raf activtes

Answer 15

MAPKK

Question 16

MAPKK activates

Answer 16

MAP- kinase whcih drives growth, differentition adn proliferation

Question 17

PI3 can bind to IRS via SH2 domain, this leads to generation of

Answer 17

PIP3

Question 18

PIP3 is a binding parter for proteins with PH domains eg

Answer 18

AKT

Question 19

PI3K adds a phosphorylates PIP3

Answer 19

PDK1 binds to PIP3 and it enables the phosphorylation of a redisue on AKT

Question 20

mTORC2 phosphorylates AKT

Answer 20

dual phosphorylation activates AKT

Question 21

when AKT is phosphorylated it can phosphorylate other proteins
AS160 blocks movement of vesicles containing GLUT4 by

Answer 21

regulating Rab

Question 22

for Ran to facilitate the movement to the membrane it needs to be bound to

Answer 22

GTP when AS160 prevents them binding

Question 23

phosphorylation of AKT leads to phosphorylation of

Answer 23

AS160 leading to its inactivation causing GLUT4 to translocate

Question 24

AKT phosphorylates TSC2 which regulates

Answer 24

mTORC1

Question 25

activation of mTORC1 activates elF4E-BP1 and S6K1 leads to translation initiation adn ribosome biogensis

Answer 25

protein synthesis ^

Question 26

FOXO1 induces G6PC and PEPCK (enzymes of gluconeogenesis) and FOXO1 represses GCK (glucokinase) AKT phosphorylates FOXO1 which then translocates to the cytoplasm wheres its

Answer 26

ubiquitinated and degreaded allowing repression og G6PC and PEPCK and insuction og glucokinase

Question 27

glycogen sythase kinase 3 (GSK3) is inactivates when phosphorylated by AKT, GSK when is activate is able to phosphorylate many proteins

Answer 27

GSK phosphorylaltes glycogen synthase making it inactive and not mych glycogen is formed AKT phosphorylates GSK3 making it inactive promoting glycogen Nand protein synthsis