Orthogenesis - “Straight-line evolution,” held that the variation that arises is directed toward fixed goals.

TLS Online TPP Program

#Id: 9661

#XL - T Zoology

Activated RTKs and cytokine receptors promote PLCγ activity in two ways: 

By localizing PLCγ to the membrane

By phosphorylating PLCγ

TLS Online TPP Program

#Id: 9662

#XL - T Zoology

The SH2 domains of PLCγ bind to specific phosphotyrosines on the activated RTKs and cytokine receptors, thus positioning PLCγ close to PIP2.

TLS Online TPP Program

#Id: 9663

#XL - T Zoology

Kinase activity associated with receptor activation phosphorylates tyrosines on the bound PLCγ, enhancing its hydrolase activity. 

TLS Online TPP Program

#Id: 9664

#XL - T Zoology

Activated RTKs and cytokine receptors initiate another phosphoinositide pathway by recruiting PI-3 kinase to the cytosolic surface of the plasma membrane.

TLS Online TPP Program

#Id: 9665

#XL - T Zoology

PI-3 kinase contains SH2 domain which binds to phosphotyrosines on the activated RTKs and cytokine receptors

TLS Online TPP Program

#Id: 9666

#XL - T Zoology

PI-3 kinase adds a phosphate to the 3′ carbon in one of two separate PI substrates, leading to formation of two PI 3-phosphates: PI(3,4)P2 or PI(3,4,5)P3