title: Switching of bovine cytochrome c oxidase subunit VIa isoforms in skeletal muscle during development.
abstract: A cDNA encoding the liver isoform of bovine cytochrome c oxidase subunit VIa (VIaL) was cloned from bovine liver RNA by reverse transcription and the polymerase chain reaction. The nucleotide and deduced amino acid sequences show high conservation with the corresponding rat and human liver subunits. The sequence similarity between beef heart and beef liver VIa is 60%. Northern analyses of the steady-state levels of the VIa-heart (VIaH) and VIa-liver (VIaL) transcripts showed that adult liver and brain contained only VIaL transcripts, the VIaH transcript predominated in heart with a small amount of VIaL also present, while in adult skeletal muscle VIaH was present exclusively. The VIaL transcript was found in heart with a small amount of VIaL also present, while in adult skeletal muscle VIaH was present exclusively. The VIaL transcript was found in fetal heart and skeletal muscle from 104-215-day-old fetuses, in as much as 25% of the amount of VIaH transcript. The down-regulation of VIaL transcript in skeletal muscle at or close to birth may be correlated with a change in amount of cytochrome c oxidase relative to the bc1 complex (complex III) observed spectrally when fetal and adult muscle samples were compared.
authors.affiliation: Institute of Molecular Biology, University of Oregon, Eugene 97403.
authors.forename: G D
authors.initials: GD
authors.lastname: Ewart
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Zhang
authors.forename: R A
authors.initials: RA
authors.lastname: Capaldi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002417:Cattle; D004247:DNA / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism*; D005333:Fetus / Q000201:enzymology; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D024510:Muscle Development; D009132:Muscles / Q000201:enzymology*; D012313:RNA / Q000235:genetics; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
chemical_list: D007527:Isoenzymes; D012313:RNA; D004247:DNA; D003576:Electron Transport Complex IV