The nuclear ubiquitin-proteasome system degrades MyoD
The nuclear ubiquitin-proteasome system degrades MyoD
复制标题
DOI：
10.1074/jbc.m009388200
复制
发表时间：
2001-06-22
影响因子：
4.8
通讯作者：
Schwartz, AL
中科院分区：
文献类型：
--
作者：
Floyd, ZE;Trausch-Azar, JS;Schwartz, AL
许多短寿命的核蛋白被泛素-蛋白酶体途径降解。虽然泛素-蛋白酶体系统的许多组分都位于细胞核中，但细胞核在调节这些蛋白质周转中的作用还没有很好的定义。我们已经使用了高度纯化的HeLa细胞核的核质来研究泛素-蛋白酶体系统（MyoD）的生理底物的降解。使用该系统抑制剂的体外研究表明，MyoD通过HeLa核质中的遍在蛋白-蛋白酶体途径降解。体外纯化的核质也支持高分子量MyoD-泛素加合物的产生。此外，使用来普霉素B抑制核输出的体内研究表明，MyoD在HeLa细胞中通过核泛素-蛋白酶体系统降解。
Many short-lived nuclear proteins are targeted for degradation by the ubiquitin-proteasome pathway. The role of the nucleus in regulating the turnover of these proteins is not well defined, although many components of the ubiquitin-proteasome system are localized in the nucleus. We have used nucleoplasm from highly purified HeLa nuclei to examine the degradation of a physiological substrate of the ubiquitin-proteasome system (MyoD). lit vitro studies using inhibitors of the system demonstrate MyoD is degraded via the ubiquitin-proteasome pathway in HeLa nucleoplasm. Purified nucleoplasm in vitro also supports the generation of high molecular mass MyoD-ubiquitin adducts. In addition, in vivo studies, using leptomycin B to inhibit nuclear export, demonstrate that MyoD is degraded in HeLa cells by the nuclear ubiquitin-proteasome system.