Procollagen binds to both prolyl 4‐hydroxylase/protein disulfide isomerase and HSP47 within the endoplasmic reticulum in the absence of ascorbate

FEBS Letters

Nagata, Kazuhiro¹  Hosokawa, Nobuko¹ 

[1] Department of Molecular and Cellular Biology, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8397, and Core Research for Evolutional Science and Technology, JST, Japan

关键词: Procollagen;    Chaperone protein;    HSP47;    Protein disulfide isomerase;    Prolyl 4-hydroxylase;    ER;    endoplasmic reticulum;    PDI;    protein disulfide isomerase;    HSP;    heat shock protein;    GRP;    glucose-regulated protein;    BiP;    heavy chain binding protein;    SDS-PAGE;    sodium dodecyl sulfate-polyacrylamide gel electrophoresis;    P4-H;    prolyl 4-hydroxylase;    DTT;    dithiothreitol;    DSP;    dithiobis(succinimidylpropionate);   

DOI  :  10.1016/S0014-5793(99)01713-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In cells, only properly folded procollagen trimers are secreted from the endoplasmic reticulum (ER), while improperly folded abnormal procollagens are retained within the ER. Ascorbic acid is a co-factor in procollagen hydroxylation, which in turn is required for trimer formation. We examined chaperone proteins which bound to procollagen in the absence of ascorbic acid, a model which mimics the human disease scurvy at the cellular level. We found that both prolyl 4-hydroxylase (P4-H)/protein disulfide isomerase (PDI) and HSP47 bound to procollagen in the absence of ascorbic acid. However, the binding of PDI to procollagen decreased when HSP47 was co-transfected, suggesting that HSP47 and PDI compete for binding to procollagen. These data indicate that P4-H/PDI and HSP47 have cooperative but distinct chaperone functions during procollagen biosynthesis.

【 授权许可】

Unknown