TLS Online TPP Program

#Id: 9667

#Unit 4. Cell Communication and Cell Signaling

In cells, PI-3 kinase pathway :

Triggers cell division 

Prevents apoptosis

Induces specific changes in cell metabolism

TLS Online TPP Program

#Id: 9668

#Unit 4. Cell Communication and Cell Signaling

An important signal transduction protein that binds to PI 3-phosphates is protein kinase B (Akt),  a serine/threonine kinase

TLS Online TPP Program

#Id: 9669

#Unit 4. Cell Communication and Cell Signaling

PI-3 kinase was first identified in studies of the 

polyoma virus, a DNA virus

TLS Online TPP Program

#Id: 9670

#Unit 4. Cell Communication and Cell Signaling

PKB contains:

A PH domain

A kinase domain

TLS Online TPP Program

#Id: 9671

#Unit 4. Cell Communication and Cell Signaling

PH domain of PKB binds with high affinity to the 

3-phosphates in both PI(3,4)P2 and PI(3,4,5)P3

TLS Online TPP Program

#Id: 9672

#Unit 4. Cell Communication and Cell Signaling

In unstimulated cells, 

concentration of phosphoinositides is low, and PKB is

inactive because its PH domain physically blocks the kinase active site