Structure and chromosomal location of the bovine gene for the heart muscle isoform of cytochrome c oxidase subunit VIII.
We have isolated the bovine COX8H gene for the heart/muscle isoform of cytochrome c oxidase (COX) subunit VIII from a library of bovine genomic DNA cloned into lambda EMBL3. Primer extension assays on bovine heart mRNA mapped the 5' ends of COX8H transcripts to a CA dinucleotide 62-bp upstream from the ATG codon. The gene thus spans 1565-bp and comprises two exons and one large intron of 1227 bp. Exon 1 encodes the 5' untranslated region, a 24-amino acid presequence, and the first 13 amino acids of the mature COX VIII-H protein. Exon 2 encodes the remainder of the cDNA: amino acids 14 to 46 plus the 66-bp 3' untranslated region. The exon-intron boundaries matched the consensus splice junction sequences. Two protein polymorphisms were seen: an Ala/Val polymorphism at position -6 in the presequence and the previously noted Lys/Arg polymorphism at residue 7 of the mature protein. A TaqI polymorphism occurs in the intron. The COX8H gene was mapped by bovine x rodent somatic cell hybrid mapping panels to bovine (BTA) Chromosome (Chr) 25 with 100% concordancy. BTA 25 is conserved relative to the long arm of human (HSA) Chr 11, which contains COX8, the gene for the single human COX VIII subunit that is homologous to the liver isoform.
Lomax
M I
MI
Department of Anatomy and Cell Biology, University of Michigan, Ann Arbor 48109, USA.
Riggs
P K
PK
Womack
J E
JE
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle / Q000235:genetics*; D002874:Chromosome Mapping; D003576:Electron Transport Complex IV / Q000235:genetics*; D005091:Exons / Q000235:genetics; D015870:Gene Expression; D005796:Genes; D006801:Humans; D006822:Hybrid Cells; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000235:genetics*; D009206:Myocardium / Q000201:enzymology*; D013045:Species Specificity
D009124:Muscle Proteins; D003576:Electron Transport Complex IV