Question

What are the individual roles of each of the following components of the Wnt/Beta-Catenin pathway?

- GSK3:

- APC:

- Axin:

Answer 1

Answer:-

GSK3:- it is an important enzyme in wnt pathway. It phosphorylates the B-catenin.this results in degradation of the b-catenin molecule. It also phosphorylate the axin ant APC. As the b-catenin is degraded, it does not reach the nucleus and displace the transcriptional repressors and do not activate the genes.

APC-the apc gene codes for the APC protein. This protein acts as a tumor supressor and prevents the cell proliferation. It acts through the wnt pathway. Any defect in this gene results in familial adenomatous polyposis.

AXIN:--axin is encoded by axin1 gene. By interacting with b-catenin, APC, it inhibits the wnt signalling pathway. It plays dual role, on one hand it degrades the b-catenin, resulting is stopping of the pathway. On the other it increases the LRP-5/6 phosphorylation resulring in activation of the pathway.