Differential expression of genes specifying two isoforms of subunit VIa of human cytochrome c oxidase.
Subunit VIa of mammalian cytochrome c oxidase (COX; EC 1.9.3.1) exists in two isoforms, one present ubiquitously ('liver' isoform; COX VIa-L) and the other present only in cardiac and skeletal muscle (COX VIa-M). We have now isolated a full-length cDNA specifying human COX VIa-M. The deduced mature COX VIa-M polypeptide is 62% identical to the human COX VIa-L isoform, but is approximately 80% identical to the bovine and rat COX VIa-M isoforms, suggesting that the two COX VIa isoform-encoding genes arose prior to the mammalian radiation. Transcriptional analysis showed a tissue-specific pattern: whereas COXVIa-L is transcribed ubiquitously, COXVIa-M is transcribed only in heart and skeletal muscle. The cDNA specifying COX VIa-M is a prime candidate for use in investigations of Mendelian-inherited COX deficiencies with primary involvement of muscle.
Fabrizi
G M
GM
H. Houston Merritt Clinical Research Center for Muscular Dystrophy and Related Disorders, Columbia University College of Physicians and Surgeons, New York, NY 10032.
Sadlock
J
J
Hirano
M
M
Mita
S
S
Koga
Y
Y
Rizzuto
R
R
Zeviani
M
M
Schon
E A
EA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D030401:Cytochrome-c Oxidase Deficiency; D004247:DNA; D003576:Electron Transport Complex IV / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D008969:Molecular Sequence Data; D009132:Muscles / Q000201:enzymology*; D009928:Organ Specificity / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D007527:Isoenzymes; D004247:DNA; D003576:Electron Transport Complex IV