Loss of BiP/GRP78 function blocks translocation of secretory proteins in yeast.

作者：Joseph P. Vogel, Leanne M. Misra, Mark David Rose · 发表于：The Journal of Cell Biology · 年份：1990 · DOI：10.1083/jcb.110.6.1885 · 被引用次数：437 · 研究领域：Endoplasmic Reticulum Stress and Disease、Fungal and yeast genetics research、Cellular transport and secretion

BiP/GRP78 is an essential member of the HSP70 family that resides in the lumen of the endoplasmic reticulum. In yeast, BiP/GRP78 is encoded by the KAR2 gene. A temperature sensitive mutation was isolated in KAR2 and found to cause a rapid block in protein secretion. Secretory precursors of a number of proteins (invertase, carboxypeptidase Y, alpha-factor, and BiP) accumulated that were characteristic of a block in translocation into the lumen of the ER. Protease protection experiments confirmed that the precursors accumulated on the cytoplasmic side of the ER membrane. Moreover, depletion of wild-type KAR2 protein also resulted in a block in translocation of secretory proteins. These results implicate BiP/GRP78 function in the continued translocation of proteins into the lumen of the ER.