Ubiquitin

PTEN, a tumor suppressor, has been implicated in a large number of human tumors and is conserved from humans to worms. Characterization of PTEN protein showed that it is a phosphatase that acts on proteins and on 3-phosphorylated phosphoinositides, and can therefore modulate signaltransduction pathways that involve lipid second messengers. Recent results indicate that at least part of its role is to regulate the activity of the serine/threonine kinase AKT/PKB, and thus influence cell survival signaling.

References:

1. Degradation of C-terminal truncated alpha A-crystallins by the ubiquitin-proteasome pathway. Invest Ophthalmol Vis Sci 2007 Sep;48(9):4200-8
2. Ubiquitin carboxyl-terminal hydrolase L1, a novel deubiquitinating enzyme in the va sculature, attenuates NF-kappaB activation. Arterioscler Thromb Vasc Biol 2007 Oct;27(10):2184-90
3. Global changes to the ubiquitin system in Huntington's disease. Nature 2007 Aug 9;448(7154):704-8
4. Structural basis for ubiquitin-mediated dimerization and activation of the ubiquitin protein ligase Cbl-b. Mol Cell 2007 Aug 3;27(3):474-85
5. APC/C(Cdc20) controls the ubiquitin-mediated degradation of p21 in prometaphase. Mol Cell 2007 Aug 3;27(3):462-73
6. The adaptor molecule CIN85 regulates Syk tyrosine kinase level by activating the ubiquitin-proteasome degradation pathway. J Immunol 2007 Aug 15;179(4):2089-96