The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

SAG/ROC-SCFbeta-TrCP E3 ubiquitin ligase promotes pro-caspase-3 degradation as a mechanism of apoptosis protection.

Skp1-cullin-F-box protein ( SCF) is a multicomponent E3 ubiquitin (Ub) ligase that ubiquitinates a number of important biologic molecules such as p27, beta-catenin, and IkappaB for proteasomal degradation, thus regulating cell proliferation and survival. One SCF component, SAG/ ROC2/Rbx2/Hrt2, a RING finger protein, was first identified as a redox-inducible protein, which, when overexpressed, inhibited apoptosis both in vitro and in vivo. We report here that sensitive to apoptosis gene (SAG), as well as its family member ROC1/Rbx1, bound to the proinactive form of caspase-3 (pro-caspase-3). Binding was likely mediated through F-box protein, beta-transducin repeat-containing protein (beta-TrCP), which binds to the first 38 amino acids of pro-caspase-3. Importantly, beta-TrCP1 expression significantly shortened the protein half-life of pro-caspase-3, whereas expression of a dominant-negative beta-TrCP1 mutant with the F-box domain deleted extended it. An in vitro ubiquitination assay showed that SAG/ROC-SCF(beta-TrCP) promoted ubiquitination of pro-caspase-3. Furthermore, endogenous levels of pro-caspase-3 were decreased by overexpression of SAG/ROC-SCF(beta-TrCP) E3 Ub ligases, but increased on siRNA silencing of SAG, regulator of cullin-1 ( ROC1), or beta-TrCPs, leading to increased apoptosis by etoposide and TNF-related apoptosis-inducing ligand through increased activation of caspase-3. Thus, pro-caspase-3 appears to be a substrate of SAG/ROC-SCF(beta-TrCP) E3 Ub ligase, which protects cells from apoptosis through increased apoptosis threshold by reducing the basal level of pro-caspase-3.[1]


  1. SAG/ROC-SCFbeta-TrCP E3 ubiquitin ligase promotes pro-caspase-3 degradation as a mechanism of apoptosis protection. Tan, M., Gallegos, J.R., Gu, Q., Huang, Y., Li, J., Jin, Y., Lu, H., Sun, Y. Neoplasia (2006) [Pubmed]
WikiGenes - Universities