期刊
MOLECULAR BIOLOGY OF THE CELL
卷 18, 期 9, 页码 3681-3691出版社
AMER SOC CELL BIOLOGY
DOI: 10.1091/mbc.E07-03-0272
关键词
-
类别
资金
- Intramural NIH HHS Funding Source: Medline
- NHLBI NIH HHS [R01 HL052173, R01 HL-052173] Funding Source: Medline
- NIDDK NIH HHS [R01 DK042394, R01 DK-042394] Funding Source: Medline
The preemptive quality control (pQC) pathway protects cells from acute endoplasmic reticulum (ER) stress by attenuating translocation of nascent proteins despite their targeting to translocons at the ER membrane. Here, we investigate the hypothesis that the DnaJ protein p58(IPK) plays an essential role in this process via HSP70 recruitment to the cytosolic face of translocons for extraction of translocationally attenuated nascent chains. Our analyses revealed that the heightened stress sensitivity of p58(-/-) cells was not due to an impairment of the pQC pathway or elevated ER substrate burden during acute stress. Instead, the lesion was in the protein processing capacity of the ER lumen, where p58(IPK) was found to normally reside in association with BiP. ER lumenal p58(IPK) could be coimmunoprecipitated with a newly synthesized secretory protein in vitro and stimulated protein maturation upon overexpression in cells. These results identify a previously unanticipated location for p58(IPK) in the ER lumen where its putative function as a cochaperone explains the stress-sensitivity phenotype of knockout cells and mice.
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