Supplementary Figure 3 from Degradation of Tob1 Mediated by SCFSkp2-Dependent Ubiquitination

Hiramatsu, Yoshihiro; Kitagawa, Kyoko; Suzuki, Toru; Uchida, Chiharu; Hattori, Takayuki; Kikuchi, Hirotoshi; Oda, Toshiaki; Hatakeyama, Shigetsugu; Nakayama, Keiichi I.; Yamamoto, Tadashi; Konno, Hiroyuki; Kitagawa, Masatoshi

doi:10.1158/0008-5472.22365479.v1

Supplementary Figure 3 from Degradation of Tob1 Mediated by SCF^Skp2-Dependent Ubiquitination

journal contribution

posted on 2023-03-30, 16:49 authored by Yoshihiro Hiramatsu, Kyoko Kitagawa, Toru Suzuki, Chiharu Uchida, Takayuki Hattori, Hirotoshi Kikuchi, Toshiaki Oda, Shigetsugu Hatakeyama, Keiichi I. Nakayama, Tadashi Yamamoto, Hiroyuki Konno, Masatoshi Kitagawa

Supplementary Figure 3 from Degradation of Tob1 Mediated by SCF^Skp2-Dependent Ubiquitination

History

ARTICLE ABSTRACT

Tob1, a member of the Tob/BTG family, is involved in the control of G1-S progression by suppressing cyclin D1 expression and acts as a tumor suppressor gene. Tob1 was reported to have a quick turnover through the ubiquitin-proteasome pathway, but proteins involved in this process are still unknown. We showed that Skp2, a substrate-targeting subunit of the SCF (Skp1/Cul1/F-box protein) ubiquitin ligase complex, was involved in ubiquitin-dependent degradation of Tob1. Skp2 interacted with Tob1 and facilitated ubiquitination of Tob1 in intact cells as well as in vitro. Skp2 mutants without the F-box or leucine rich repeat were not able to bind to Tob1 and did not enhance ubiquitination of Tob1. Tob1 was stabilized in both Skp2−/− mouse fibroblasts and Skp2 knockdown HeLa cells. Moreover, cyclin D1 expression was suppressed in Skp2 knockdown HeLa cells. These data suggest that Tob1 is a novel target for degradation by the SCF-Skp2 ubiquitin ligase. (Cancer Res 2006; 66(17): 8477-83)