Tissue-specific expression and chromosome assignment of genes specifying two isoforms of subunit VIIa of human cytochrome c oxidase

Gene. 1992 Oct 1;119(2):299-305. doi: 10.1016/0378-1119(92)90287-y.


Subunit VIIa of mammalian cytochrome c oxidase (COX; EC exists in at least two isoforms, one present in all tissue types ('liver' isoform; COX VIIa-L) and the other specific for cardiac and skeletal muscle (COX VIIa-M). We have isolated a full-length cDNA encoding human COX VIIa-M. The deduced polypeptide represents the human ortholog of COX VIIa-M, as it shares 78% identity with bovine COX VIIa-M, but only 63% identity with human COX VIIa-L. Northern-blot analysis of primate tissues demonstrated that COXVIIa-M mRNA is present only in muscle tissues; in contrast, the COXVIIa-L mRNA is present in both muscle and nonmuscle tissues. Southern-blot hybridization of human-rodent cell hybrid genomic DNA indicates that the COXVIIa-M gene maps to a single locus on chromosome 19, designated COX7AM. In contrast, COXVIIa-L cDNA probes hybridized to fragments from two COX7AL loci, on chromosomes 4 and 14.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Chromosome Mapping
  • Chromosomes, Human, Pair 19*
  • Cytochrome-c Oxidase Deficiency
  • DNA
  • Electron Transport Complex IV / genetics*
  • Humans
  • Isoenzymes / genetics*
  • Molecular Sequence Data
  • Muscles / enzymology*
  • Organ Specificity / genetics
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Transcription, Genetic


  • Isoenzymes
  • DNA
  • Electron Transport Complex IV

Associated data

  • GENBANK/D10364
  • GENBANK/D10365
  • GENBANK/D10366
  • GENBANK/M74891
  • GENBANK/M74892
  • GENBANK/M79309
  • GENBANK/M79310
  • GENBANK/M83186
  • GENBANK/M90357
  • GENBANK/S43297