Shy1p occurs in a high molecular weight complex and is required for efficient assembly of cytochrome c oxidase in yeast

FEBS Letters

Feenstra, M.²  Grivell, L.A.²  Bucko, M.²  Zeviani, M.¹  Artal Sanz, M.²  Farhoud, M.H.²  Hakkaart, G.A.J.²  Nijtmans, L.G.J.² 

[1] National Neurological Institute ‘C. Besta’, Milan, Italy;Section for Molecular Biology, Swammerdam Institute of Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands

关键词: SURF1;    SHY1;    Cytochrome c oxidase;    Leigh syndrome;    Protein assembly;    COX;    cytochrome c oxidase;    2D-PAGE;    two-dimensional polyacrylamide gel electrophoresis;    BN-PAGE;    blue native polyacrylamide gel electrophoresis;   

DOI  :  10.1016/S0014-5793(01)02447-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Surf1p is a protein involved in the assembly of mitochondrial respiratory chain complexes. However its exact role in this process remains to be elucidated. We studied SHY1, the yeast homologue of SURF1, with an aim to obtain a better understanding of the molecular pathogenesis of cytochrome c oxidase (COX) deficiency in SURF1 mutant cells from Leigh syndrome patients. Assembly of COX was analysed in a shy1 null mutant strain by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). Steady-state levels of the enzyme were found to be strongly reduced, the total amount of assembled complex being approximately 30% of control. The presence of a significant amount of holo-COX in the SHY1-disruptant strain suggests that Shy1p may either facilitate assembly of the enzyme, or increase its stability. However, our observations, based on 2D-PAGE analysis of mitochondria labelled in vitro, now provide the first direct evidence that COX assembly is impaired in a Δshy1 strain. COX enzyme assembled in the absence of Shy1p appears to be structurally and enzymically normal. The in vitro labelling studies additionally indicate that mitochondrial translation is significantly increased in the shy1 null mutant strain, possibly reflecting a compensatory mechanism for reduced respiratory capacity. Protein interactions of both Shy1p and Surf1p are implied by their appearance in a high molecular weight complex of about 250 kDa, as shown by 2D-PAGE.

【 授权许可】

Unknown