Modifications of the lipoamide-containing mitochondrial subproteome in a yeast mutant defective in cysteine desulfurase.
Comparison and identification of mitochondrial matrix proteins from wild-type and cysteine desulfurase-defective (nfs1-14, carrying a hypomorphic allele of NFS1) yeast strains, using two-dimensional gel electrophoresis coupled to mass spectrometry analyses, revealed large changes in the amounts of various proteins. Protein spots that were specifically increased in the nfs1-14 mutant included subunits of lipoamide-containing enzyme complexes: Kgd2, Lat1, and Gcv3, subunits of the mitochondrial alpha-ketoglutarate dehydrogenase, pyruvate dehydrogenase, and glycine cleavage system complexes, respectively. Moreover the increased protein spots corresponded to lipoamide-deficient forms in the nfs1-14 mutant. The increased proteins migrated as separate, cathode-shifted spots, consistent with gain of a lysine charge due to lack of lipoamide addition. Lack of lipoylation of these proteins was further validated using an antibody specific for lipoamide-containing proteins. In addition, this antibody revealed a fourth lipoamide-containing protein, probably corresponding to the E2 component of the branched-chain keto acid dehydrogenase complex. Like the lipoamide-containing forms of Kgd2, Lat1, and Gcv3, this protein also showed decreased lipoic acid reactivity in the nfs1-14 mutant. Cysteine desulfurases, such as yeast NFS1, are required for sulfur addition to iron-sulfur clusters and other sulfur-requiring processes. The results demonstrate that Nfs1 protein is required for the proper post-translational modification of the lipoamide-containing mitochondrial subproteome in yeast and pave the road toward a thorough understanding of its precise role in lipoic acid synthesis.[1]References
- Modifications of the lipoamide-containing mitochondrial subproteome in a yeast mutant defective in cysteine desulfurase. Onder, O., Yoon, H., Naumann, B., Hippler, M., Dancis, A., Daldal, F. Mol. Cell Proteomics (2006) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
