Question

Akt is also known as protein kinase B

List all Secondary Messengers

Phosphoinositide 3Kinase is a heterodimer with two subunits. The regulatory subunit binds IRS-1. The kinase subunit interacts with PIP₂. Why do you think overproduction of the regulatory subunit leads to insulin resistance associated with type 2 diabetes?

Answer 1

Answer -

Insulin work with RAS independent pathway .phosphorylation of insulin receptors activate IRS 1 . This protein perform major function

1-fussion of GLUT vessicle on the cell membrane

2- Internalization of GPCR​

3- activation of ERK -1and ELK -1 protein for cell division

​​​​​Activation of PKB - insulin activate PKB that phosphrylate membrene inositol residue this is call phosphoinositol pathway .this pathway is regulated by both GPCR and RTK  

an enzyme PKB recognize PI3, 4 biphosphate and partially activated further PSK 1 and PDK -2 fully activated PKB .

Function of PKB - PKB phosphorylate Bad ( proapoptotic protein) making it's inactive.

2- PKB also phosphorylates foxo3a (proapoptotic protein ).

Mechanism of PKB is inhibited by pTEN phosphatase

PKB inactivate proapoptotic protein (Bad foxo3a) . So the loss of function of PKB causes apoptosis .

Over production of PKB leads to insulin resistance associated with type 2 diabetes .because PKB leads to fussion of glut vessicle on the cell membrane

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