Question

5. The insulin receptor substrate 1 (IRS) assists in reactivation of the insulin receptor by __________ of PTP1B, which in turn _________ the insulin receptor.

phosphorylation; phosphorylates

dephosphorylation; dephosphorylates

phosphorylation; dephosphorylates

dephosphorylation; phosphorylates

8. A comparison of the insulin signaling pathway in Homo sapiens, Alligator mississppiensis, and Falco cherrug indicates that this pathway is _____ conserved, with the exception of factors associated with ________ in the American alligator.

highly; antiapoptosis

not highly; antiapoptosis

highly; apoptosis

not highly; apoptosis

10. Which protein factor is found in the nucleus?

Ste2

Ste5

Ste7

Ste12

Answer 1

5) Answer : phosphorylation; phosphorylates

PTP1B (protein tyrosine phosphatase) is a negative regulator for insuling signalling pathway. Therefore, dephosphorylation of PTP1B can dephosphorylate insulin receptor and inactivate it.

10) Answer : Ste12

Ste12 : It is found in nucleus as it is a

DNA-binding transcriptional transactivator

Ste5 : It acts as adapter and scaffold as it has no catalytic activity and it is the second effector for G? subunit, MAPK cascade kinases. It is found predominantly in the nucleus or shuttles between cytoplasm and nucleus.

Ste7	: It is cytoplasmic protein which is involved in MEK (MAPK/ERK kinase)

Ste2 :

G-protein coupled pheromone receptors