| First Author | Prince AM | Year | 2002 |
| Journal | Biochem Biophys Res Commun | Volume | 290 |
| Issue | 3 | Pages | 1066-71 |
| PubMed ID | 11798183 | Mgi Jnum | J:74783 |
| Mgi Id | MGI:2159090 | Doi | 10.1006/bbrc.2001.6291 |
| Citation | Prince AM, et al. (2002) Proteasomal degradation of retinoblastoma-related p130 during adipocyte differentiation. Biochem Biophys Res Commun 290(3):1066-71 |
| abstractText | Within 24 h of hormonally stimulated 3T3-L1 adipocyte differentiation, there are dramatic changes in the protein levels of p130 and p107, two members of the retinoblastoma tumor suppressor gene family. Designated the 'p103:p107' switch, this alteration is characterized by a rapid and transient drop in p130 protein levels accompanied by a transient increase in both p107 mRNA and protein levels. Using protease inhibitors, the specific proteolytic pathway involved in degradation of p130 was examined. Treatment of cells with N-acetyl-leu-leu-norleucinal, an inhibitor that blocks proteolytic activity of type I calpain and the 26S proteasome, resulted in a complete block in the degradation of p130 protein, as well as adipocyte differentiation, suggesting that one of these pathways is involved in regulating p130 protein levels. Similar analysis with lactacystin, a specific inhibitor of the 26S proteasome, also resulted in a complete block in both differentiation and p130 degradation. Furthermore, both inhibitors blocked the increase in p107 protein levels normally observed on Day 1, suggesting that the p130:p107 switch is required for adipocyte differentiation and one of the early molecular events involved in activating the p130:p107 switch is the specific degradation of p130 by the 26S proteasome. |
