TY - JOUR
T1 - The rat cytochrome c oxidase subunit IV gene family
T2 - Tissue-specific and hormonal differences in subunit IV and cytochrome c mRNA expression
AU - Virbasius, Joseph V.
AU - Scarpulla, Richard C.
N1 - Funding Information:
We thank Dr. L. Grossman for providing the human cytochrome c oxidase subunit IV cDNA clone, D. Good for isolating the rat testis cDNA clone, and the Northwestern University Biotechnology Facilities for synthesis of oligonucleotides. This work was supported by U.S. Public Health Service grant GM32525 from the National Institutes of Health. R.C.S. is the recipient of Faculty Research Award FRA-361 from the American Cancer Society.
PY - 1990/11/25
Y1 - 1990/11/25
N2 - We have isolated three members of the rat cytochrome c oxidase subunit IV gene family: one functional gene and two processed pseudogenes. The pseudogenes appear to represent the only other closely related sequences in this family. The functional gene encodes an isoform which is expressed in all tissues examined and has features characteristic of 'housekeeping' genes. These include multiple transcription start sites mapped to within an approximately 50 bp region and a GC-rich promoter lacking typical CCAAT or TATAA sequences. Although the subunit IV gene is expressed at its highest levels in cardiac and skeletal muscle, consistent with the high energy demand in those tissues, its expression differs from that of cytochrome c in several respects. 1) Subunit IV mRNA abundance in various tissues is relatively uniform when compared to the highly variable levels of cytochrome c mRNAs. 2) Unlike cytochrome c, subunit IV mRNA is expressed at a surprisingly high level in testis. 3) While cytochrome c mRNA levels in liver are increased markedly in response to thyroid hormone treatment, subunit IV mRNA is not significantly affected. Differences in the expression of these two nuclear-encoded respiratory genes are consistent with differences in regulatory elements within their promoters. Therefore, the regulation of nuclear-encoded respiratory genes in response to tissue demands for cellular energy may not be satisfactorily explained by a set of universal regulators common to all such genes.
AB - We have isolated three members of the rat cytochrome c oxidase subunit IV gene family: one functional gene and two processed pseudogenes. The pseudogenes appear to represent the only other closely related sequences in this family. The functional gene encodes an isoform which is expressed in all tissues examined and has features characteristic of 'housekeeping' genes. These include multiple transcription start sites mapped to within an approximately 50 bp region and a GC-rich promoter lacking typical CCAAT or TATAA sequences. Although the subunit IV gene is expressed at its highest levels in cardiac and skeletal muscle, consistent with the high energy demand in those tissues, its expression differs from that of cytochrome c in several respects. 1) Subunit IV mRNA abundance in various tissues is relatively uniform when compared to the highly variable levels of cytochrome c mRNAs. 2) Unlike cytochrome c, subunit IV mRNA is expressed at a surprisingly high level in testis. 3) While cytochrome c mRNA levels in liver are increased markedly in response to thyroid hormone treatment, subunit IV mRNA is not significantly affected. Differences in the expression of these two nuclear-encoded respiratory genes are consistent with differences in regulatory elements within their promoters. Therefore, the regulation of nuclear-encoded respiratory genes in response to tissue demands for cellular energy may not be satisfactorily explained by a set of universal regulators common to all such genes.
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U2 - 10.1093/nar/18.22.6581
DO - 10.1093/nar/18.22.6581
M3 - Article
C2 - 2174541
AN - SCOPUS:0025185340
SN - 0305-1048
VL - 18
SP - 6581
EP - 6586
JO - Nucleic acids research
JF - Nucleic acids research
IS - 22
ER -