AKT Signaling Pathway: Regulation by the Insulin Signaling Cascade

The video tutorial explains the insulin signaling pathway, focusing on the AKT pathway's regulation. It covers insulin binding, IRS phosphorylation, PI3K activation, and the roles of PDK1 and mTOR complexes. The tutorial also discusses the regulation of phosphorylation sites by phosphatases, the mechanism of glucose uptake via GLUT4, and the mTORC1 pathway's feedback regulation. The video concludes with a summary and resources for further learning.

What is the initial effect of insulin binding to its receptor on a cell?

• Inhibition of PI3K

• Activation of mTOR complex 1

• Autophosphorylation of the insulin receptor

• Dephosphorylation of IRS1 and IRS2

Which enzyme is responsible for converting PIP2 to PIP3?

• P-10

• PDK1

• PI3K

• AKT

At which sites does PDK1 phosphorylate AKT?

• Serine 473 and Threonine 308

• Threonine 308 and Serine 308

• Serine 473 and Threonine 473

• Threonine 308 and Serine 473

What role does AKT play in glucose uptake in insulin-stimulated cells?

• It phosphorylates IRS1 and IRS2

• It dephosphorylates PIP3

• It activates GLUT4 translocation

• It inhibits GLUT4 translocation

Which complex does AKT activate by inhibiting TSC2?

• PDK1

• mTOR complex 2

• mTOR complex 1

• PI3K

What is the effect of mTOR complex 1 activation on the insulin signaling pathway?

• It enhances the pathway

• It has no effect

• It inhibits the pathway

• It activates PI3K

Which protein is responsible for the negative feedback regulation of the insulin signaling pathway?

• IRS1

• P-10

• GLUT4

• P70S6K