Structural Biochemistry/Protein function/VHL

Beta-Cantenin gets jaded and von Hippel-Lindau is to blame
This research papers delves into the idea of the von Hippel-Lindau protein that is negatively regulated by beta-Catenin and Jade-1 via various mechanisms. One must first understand the proteins to connect the significance of their partnership.

Proteins Discussed
Von Hippel-Lindau is a tumor suppressor protein encoded by the VHL gene. The inactivity of the protein is associated with Von Hippel-Lindau disease. The VHL protein works through E3 ubiquitin ligase activity which targets specific proteins for degradation. However, the inactivity of the protein may cause an excess growth of cells, or a tumor. Beta-Catenin, or β-catenin, is part of a series of proteins that constitute adherens junctions and maintain epithelial cell layers in organs. The protein is used to regulate the production of VHL through negative feedback. This research paper focuses on Wnt- β-catenin which undergoes signal transduction. Wnts in particular “comprise a conserved family of secreted” (Berndt).

Jade-1 binds to β-catenin to “negatively regulates β-catenin levels in the absence of the Wnts stimulation” (Berndt). The expression of Jade-1 is what primarily determines the reduction of β-catenin. In some cases, the over expression of Jade-1 can reduce the presence of β-catenin by 50-60%. Jade-1 may be used in conjunction with VHL to regulate the production of β-catenin.

Summary of process:

Increase VHL => Increase Jade-1 => Decrease β-catenin

Decrease VHL => Decrease Jade-1 => Increase β-catenin

Mechanism Discussed
HIF-1

Reference
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TCV-4VKK6TW-1&_user=4429&_coverDate=03/31/2009&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000059602&_version=1&_urlVersion=0&_userid=4429&md5=38c4e891e16b7812a84b8685464d6ac6&searchtype=a