The Oxa1 protein is a founding member of the evolutionarily conserved Oxa1/Alb3/YidC protein family, which is involved in the biogenesis of membrane proteins in mitochondria, chloroplasts and bacteria. The predicted human homologue, Oxa1l, was originally identified by partial functional complementation of the respiratory growth defect of the yeast oxa1 mutant. Here we demonstrate that both the endogenous human Oxa1l, with an apparent molecular mass of 42 kDa, and the Oxa1l-FLAG chimeric protein localize exclusively to mitochondria in HEK293 cells. Furthermore, human Oxa1l was found to be an integral membrane protein, and, using two-dimensional blue native/denaturing PAGE, the majority of the protein was identified as part of a 600-700 kDa complex. The stable short hairpin (sh)RNA-mediated knockdown of Oxa1l in HEK293 cells resulted in markedly decreased steady-state levels and ATP hydrolytic activity of the F(1)F(o)-ATP synthase and moderately reduced levels and activity of NADH:ubiquinone oxidoreductase (complex I). However, no significant accumulation of corresponding sub-complexes could be detected on blue native immunoblots. Intriguingly, the achieved depletion of Oxa1l protein did not adversely affect the assembly or activity of cytochrome c oxidase or the cytochrome bc(1) complex. Taken together, our results indicate that human Oxa1l represents a mitochondrial integral membrane protein required for the correct biogenesis of F(1)F(o)-ATP synthase and NADH:ubiquinone oxidoreductase.
- MeSH
- 2D gelová elektroforéza MeSH
- adenosintrifosfát metabolismus MeSH
- financování organizované MeSH
- fluorescenční protilátková technika MeSH
- hydrolýza MeSH
- imunoblotting MeSH
- imunoglobulin G MeSH
- imunoprecipitace MeSH
- jaderné proteiny MeSH
- kultivované buňky MeSH
- kur domácí MeSH
- lidé MeSH
- malá interferující RNA farmakologie MeSH
- mitochondriální proteiny antagonisté a inhibitory genetika imunologie MeSH
- mitochondriální protonové ATPasy antagonisté a inhibitory biosyntéza MeSH
- mitochondrie metabolismus MeSH
- respirační komplex I antagonisté a inhibitory biosyntéza MeSH
- respirační komplex III metabolismus MeSH
- respirační komplex IV MeSH
- subcelulární frakce MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
