Monnat J, Hacker U, Geissler H, Rauchenberger R, Neuhaus E M, Maniak M, Soldati T
Department of Molecular Cell Research, Max-Planck-Institute for Medical Research, Heidelberg, Germany.
FEBS Lett. 1997 Dec 1;418(3):357-62. doi: 10.1016/s0014-5793(97)01415-4.
The primary activity of protein disulfide isomerase (PDI), a multifunctional resident of the endoplasmic reticulum (ER), is the isomerization of disulfide bridges during protein folding. We isolated a cDNA encoding Dictyostelium discoideum PDI (Dd-PDI). Phylogenetic analyses and basic biochemical properties indicate that it belongs to a subfamily called P5, many members of which differ from the classical PDIs in many respects. They lack an intervening inactive thioredoxin module, a C-terminal acidic domain involved in Ca2+ binding and a KDEL-type retrieval signal. Despite the absence of this motif, the ER is the steady-state location of Dd-PDI, suggesting the existence of an alternative retention mechanism for P5-related enzymes.
蛋白质二硫键异构酶（PDI）是内质网（ER）中的一种多功能驻留蛋白，其主要活性是在蛋白质折叠过程中二硫键的异构化。我们分离出了编码盘基网柄菌PDI（Dd-PDI）的cDNA。系统发育分析和基本生化特性表明，它属于一个名为P5的亚家族，该亚家族的许多成员在许多方面与经典的PDI不同。它们缺乏一个中间的无活性硫氧还蛋白模块、一个参与Ca2+结合的C端酸性结构域和一个KDEL型回收信号。尽管没有这个基序，但ER是Dd-PDI的稳态定位，这表明存在一种针对P5相关酶的替代保留机制。
