A role for ubiquitinylation and the cytosolic proteasome in turnover of mitochondrial uncoupling protein 1 (UCP1)
A role for ubiquitinylation and the cytosolic proteasome in turnover of mitochondrial uncoupling protein 1 (UCP1)
复制标题
DOI：
10.1016/j.bbabio.2012.03.035
复制
发表时间：
2012-10-01
影响因子：
4.3
通讯作者：
Porter, Richard K.
中科院分区：
文献类型：
--
作者：
Clarke, Kieran J.;Adams, Alison E.;Porter, Richard K.
在这项研究中，我们表明，线粒体解偶联蛋白1（UCP 1）在棕色脂肪组织（BAT）和胸腺线粒体可以被泛素化和降解的胞浆蛋白酶体。使用泛素缀合系统，我们表明，UCP 1可以在体外泛素化。我们证明，UCP 1是泛素化在体内使用分离的线粒体从棕色脂肪组织，胸腺和整个棕色脂肪细胞。使用体外泛素结合蛋白酶体降解系统，我们表明，胞质蛋白酶体可以降解UCP 1的速率与UCP 1的半衰期相当（即30-72小时，在棕色脂肪细胞和类似的3小时，在胸腺细胞）。此外，我们证明了细胞质蛋白酶体是UCP 1从线粒体降解所必需的，该过程被蛋白酶体抑制剂MG 132抑制，并且线粒体膜电位的耗散抑制UCP 1的降解。在冷适应动物的BAT线粒体中，似乎也有大量的泛素化UCP 1。我们还鉴定了分子量大于32 kDa的泛素化蛋白质（使用免疫沉淀结合质谱法）为UCP 1。我们的结论是，泛肽化和胞浆蛋白酶体在线粒体UCP 1的转换中发挥作用。本文是题为：第17届欧洲生物能学会议（EBEC 2012）的特刊的一部分。(C)2012爱思唯尔有限公司版权所有。
In this study we show that mitochondrial uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) and thymus mitochondria can be ubiquitinylated and degraded by the cytosolic proteasome. Using a ubiquitin conjugating system, we show that UCP1 can be ubiquitinylated in vitro. We demonstrate that UCP1 is ubiquitinylated in vivo using isolated mitochondria from brown adipose tissue, thymus and whole brown adipocytes. Using an in vitro ubiquitin conjugating-proteasome degradation system, we show that the cytosolic proteasome can degrade UCP1 at a rate commensurate with the half-life of UCP1 (i.e. 30-72 h in brown adipocytes and similar to 3 h, in thymocytes). In addition, we demonstrate that the cytoplasmic proteasome is required for UCP1 degradation from mitochondria that the process is inhibited by the proteasome inhibitor MG132 and that dissipation of the mitochondrial membrane potential inhibits degradation of UCP1. There also appears to be a greater amount of ubiquitinylated UCP1 associated with BAT mitochondria from cold-acclimated animals. We have also identified (using immunoprecipitation coupled with mass spectrometry) ubiquitinylated proteins with molecular masses greater than 32 kDa, as being UCP1. We conclude that there is a role for ubiquitinylation and the cytosolic proteasome in turnover of mitochondrial UCP1. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012). (C) 2012 Elsevier B.V. All rights reserved.