Turano Carlo, Coppari Sabina, Altieri Fabio, Ferraro Anna
Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche 'Alessandro Rossi-Fanelli' and Centro di Biologia Molecolare del CNR, Università 'La Sapienza', Rome, Italy.
J Cell Physiol. 2002 Nov;193(2):154-63. doi: 10.1002/jcp.10172.
Protein disulfide isomerases (PDIs) constitute a family of structurally related enzymes which catalyze disulfide bonds formation, reduction, or isomerization of newly synthesized proteins in the lumen of the endoplasmic reticulum (ER). They act also as chaperones, and are, therefore, part of a quality-control system for the correct folding of the proteins in the same subcellular compartment. While their functions in the ER have been thoroughly studied, much less is known about their roles in non-ER locations, where, however, they have been shown to be involved in important biological processes. At least three proteins of this family from higher vertebrates have been found in unusual locations (i.e., the cell surface, the extracellular space, the cytosol, and the nucleus), reached through an export mechanism which has not yet been understood. In some cases their function in the non-ER location is clearly related to their redox properties, but in most cases their mechanism of action has still to be disclosed, although their propensity to associate with other proteins or even with DNA might be the main factor responsible for their activities.
蛋白质二硫键异构酶（PDIs）构成了一类结构相关的酶家族，它们在内质网（ER）腔中催化新合成蛋白质的二硫键形成、还原或异构化。它们还充当分子伴侣，因此是同一亚细胞区室中蛋白质正确折叠的质量控制系统的一部分。虽然它们在内质网中的功能已得到充分研究，但对于它们在非内质网位置的作用却知之甚少，然而，已表明它们参与重要的生物学过程。在高等脊椎动物中，该家族至少有三种蛋白质存在于异常位置（即细胞表面、细胞外空间、细胞质和细胞核），它们是通过一种尚未被理解的输出机制到达这些位置的。在某些情况下，它们在非内质网位置的功能显然与其氧化还原特性有关，但在大多数情况下，它们的作用机制仍有待揭示，尽管它们与其他蛋白质甚至与DNA结合的倾向可能是其发挥活性的主要因素。
