|Name:||ATP synthase, H+ transporting, mitochondrial F1 complex, gamma polypeptide 1|
|PubMed (8168843):|| Jabs EW, Thomas PJ, Bernstein M, Coss C, Ferreira GC, Pedersen PL. Chromosomal localization of genes required for the terminal steps of oxidativemetabolism: alpha and gamma subunits of ATP synthase and the phosphate carrier.Hum Genet. 1994 May;93(5):600-2. PMID: 8168843 [PubMed - indexed for MEDLINE]|
The terminal steps of oxidative phosphorylation include transport of phosphate and ADP into the mitochondrial matrix, synthesis of ATP in the matrix, and transport of the product ATP into the cytosol where it can be utilized to perform cellular work. Three nuclear genome encoded membrane proteins, namely, the phosphate carrier (PHC), the adenine nucleotide carrier (ANT), and the ATP synthase complex, consisting of at least 13 individual subunits, catalyze these reactions. The locations of the alpha and gamma subunits of the mitochondrial ATP synthase complex and the mitochondrial phosphate carrier, PHC, on human chromosomes were determined using cloned rat liver cDNA as probes. Human homologues of the alpha subunit are on chromosomes 9 and 18, the gamma subunit are on chromosomes 10 and 14, and the PHC was localized to chromosome 12.
|PubMed (8227057):|| Matsuda C, Endo H, Ohta S, Kagawa Y. Gene structure of human mitochondrial ATP synthase gamma-subunit. Tissuespecificity produced by alternative RNA splicing.J Biol Chem. 1993 Nov 25;268(33):24950-8. PMID: 8227057 [PubMed - indexed for MEDLINE]|
We completely sequenced the human gene for ATP synthase gamma-subunit, which was approximately 23 kilobases long and was composed of 10 exons. Exons 1 and 2 encoded the N-terminal presequence required for mitochondrial import, while exons 9 and 10 encoded the C-terminal portions of mature protein. Enzymatic amplification of human heart and liver cDNAs using the polymerase chain reaction revealed two mRNA transcripts that were predicted to encode two 30-kDa isoforms of the gamma-subunit, which differed by the addition of a single amino acid (Asp273) at the C terminus of the liver type isoform. These two mRNA transcripts of the heart (H) type and liver (L) type were generated by alternative splicing of an exon. The same alternative splicing event was observed in bovine tissue. In human tissues, the H type mRNA devoid of exon 9 was expressed specifically in the heart and skeletal muscle, which require rapid energy supply. The L type mRNA was expressed in the brain, liver, kidney etc. Both transcripts were expressed in the skin, intestine, stomach, and aorta. This tissue specificity of transcript heterogeneity suggests the distinct functional or regulatory roles of the gamma-subunit isoforms in the catalysis of ATP synthase. This is the first report on tissue-specific isoforms generated by alternative splicing in an energy transducing mitochondrial protein.