A constitutive form of heat‐shock protein 70 is located in the outer membranes of mitochondria from rat liver

FEBS Letters

Ryan, Michael²  Lithgow, Trevor²  Høj, Peter B.²  Hoogenraad, Nicholas J.²  Anderson, Robin L.¹ 

[1] Peter MacCallum Cancer Institute, Melbourne, 3000, Australia;Department of Biochemistry, La Trobe University, Bundoora, 3083, Australia

关键词: Mitochondrial import;    Outer-membrane;    Heat-shock protein;    Photolabelling;    HSP60;    heat-shock protein of 60 kDa;    HSP70;    heat shock protein of 70 kDa;    the HSP70 isoforms referred to in the text are:HSP73;    constitutive form;    HSP72;    inducible form;    mtHSP75;    mitochondrial form;    GRP78;    endoplasmic reticulum form;    ELISA;    enzyme-linked immunosorbent assay;   

DOI  :  10.1016/0014-5793(93)80649-F

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

HSP73, the constitutive form of heat-shock protein 70, has been implicated in the translocation of preproteins across the mitochondrial membranes, being required for maintaining mitochondrial preproteins in an import competent conformation. Here we report that highly purified mitochondrial outer membranes contain a protein indistinguishable from HSP73 as a tightly associated peripheral component of the membrane. This membrane form of HSP73 was photolabelled with [α-³²P]ATP and could be released from the outer membrane with sodium carbonate, but not after incubation of the membranes with salt or with ATP. A sensitive immunoassay with an anti-HSP73 monoclonal antibody, revealed the association of HSP73 with mitochondrial outer membrane vesicles at a level similar to that of preprotein import receptors.

【 授权许可】

Unknown