期刊
TRAFFIC
卷 8, 期 10, 页码 1375-1384出版社
BLACKWELL PUBLISHING
DOI: 10.1111/j.1600-0854.2007.00616.x
关键词
copper; Ctr1p; degradation; endocytosis; Rsp5p; ubiquitin; vacuole; yeast
类别
资金
- NIGMS NIH HHS [GM61221] Funding Source: Medline
The Saccharomyces cerevisiae high-affinity copper transporter, Ctr1p, mediates cellular uptake of Cu(I). We report that when copper (50 mu M CuSO4) is added to the growth medium of copper-starved cells, Ctr1p is rapidly internalized by endocytosis, delivered to the lumen of the lysosome-like vacuole and slowly degraded by vacuolar proteases. Through analysis of the trafficking and degradation of Ctr1p mutants, two lysine residues in the C-terminal cytoplasmic tail of Ctr1p, Lys340 and Lys345, were found to be critical for copper-dependent endocytosis and degradation. In response to copper addition, Ctr1p was found to be ubiquitylated and a mutation in the Rsp5 ubiquitin ligase largely abolished ubiquitylation, endocytosis and degradation. In a strain lacking the Rsp5p accessory factors Bul1p and Bul2p, endocytosis and degradation of Ctr1p-green fluorescent protein were substantially diminished. Surprisingly, a Ctr1p mutant that lacks Lys340 and Lys345 was still ubiquitylated in a copper-dependent manner, indicating that ubiquitylation of Ctr1p on other sites is insufficient to drive copper-dependent endocytosis and degradation. This study demonstrates that copper regulates turnover of Ctr1p by stimulating Rsp5p-dependent endocytosis and degradation of Ctr1p in the vacuole.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据