Pancreas specific protein disulfide isomerase, PDIp, is in transient contact with secretory proteins during late stages of translocation

FEBS Letters

Klappa, Peter¹  Zimmermann, Richard¹  Guth, Silvia¹  Nastainczyk, Wolfgang¹  Gnau, Volker²  Volkmer, Jörg¹  Knippel, Peter¹ 

[1] Medizinische Biochemie, Universität des Saarlandes, D-66421 Homburg, Germany;Applied Biosystems GmbH, Brunnenweg 13, D-64331 Weiterstadt, Germany

关键词: Protein disulfide isomerase;    Molecular chaperone;    Protein transport;    Endoplasmic reticulum;    Secretory protein;   

DOI  :  10.1016/S0014-5793(97)00288-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Protein disulfide isomerase (PDI) and an additional lumenal protein of dog pancreas microsomes were previously observed to be in transient contact with secretory proteins during late stages of their co- or posttranslational translocation into these mammalian microsomes. The second protein was characterized as a 57 kDa glycoprotein. Here we identified this glycoprotein as the canine equivalent of human PDIp, a protein which was recently described as a new protein disulfide isomerase which is highly expressed in human pancreas. Canine PDIp is also a very abundant protein, its concentration in pancreatic microsomes approaches the concentration of PDI and of the major microsomal molecular chaperones. Apparently, PDIp shares with PDI not just the enzymatic but also the polypeptide binding or chaperoning activity. Furthermore, we suggest that PDIp, too, can be involved in completion of cotranslational as well as posttranslational translocation of proteins into mammalian microsomes.

【 授权许可】

Unknown