Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate whether RNA editing in plant mitochondria modifies structural RNAs as well as protein-coding RNAs we compared the genomic-encoded information with the respective transcripts of several genes in Oenothera. The genes analysed are the 5S, 18S and 26 S rRNAs, the alpha-subunit of ATPase (atpA), cytochrome b (cytb), orfB, which is located upstream of cytochrome oxidase subunit III, and the respective leader, trailer and spacer sequences. All open reading frames were found to be edited to some degree. The atpA coding region has the least edited mRNA in Oenothera mitochondria, with only four nucleotides altered in the 1533 nucleotide open reading frame. From this analysis we conclude that frequent RNA editing is indicative of functional protein coding regions in plant mitochondria. The extensive editing in orfB, for example, suggests that this orf codes for a mitochondrial protein. No RNA editing event was found in the 5S rRNA or in the 1824 nucleotides analysed of the 18S rRNA, but two nucleotides were found to be altered in the 1970 nucleotides compared for the 26S rRNA. One nucleotide alteration has changed C to U, the other in reverse U to C. However, only one of five cDNA clones covering this region shows the modifications, similar to many silent editing events in open reading frames. RNA editing in the structural RNAs thus does not seem to be essential for their function in the mitochondrial ribosome.
 ...
PMID:Distribution of RNA editing sites in Oenothera mitochondrial mRNAs and rRNAs. 172 5

"Helical wheel" projections of transmembrane helical segments of membrane proteins involved in proton translocation were constructed. The particular proteins studied were the uncF protein subunit of the Escherichia coli proton-ATPase, the uncE protein subunit of the E. coli proton-ATPase, and cytochrome oxidase subunit III. Clear demarcation of polar and nonpolar regions on surfaces of transmembrane helical segments was seen in the uncF protein and in uncE protein helical segment two, but not in uncE protein helical segment one. The transmembrane segment of cytochrome oxidase subunit III which includes the dicyclohexylcarbodiimide (DCCD)-reactive residue was very similar to E. coli uncE protein helical segment two. The DCCD-reactive residue in both was clearly located on a nonpolar surface.
 ...
PMID:Disposition of polar and nonpolar residues on outer surfaces of transmembrane helical segments of proteins involved in proton translocation. 609 62

Previous molecular phylogenetic studies have examined the taxonomic relationships among a number of typical emberizid sparrow genera. To help clarify these relationships, we sequenced a 1673 base pair fragment for the complete sequence of three mitochondrial genes: adenosine triphosphatase (Atp8 and Atp6) and cytochrome oxidase subunit III (COIII) for 38 sparrow species, along with Passerina amoena (Cardinalidae) and Piranga ludoviciana (Thraupidae) which were selected as the outgroups. Our analysis confirms the monophyly of traditional genera such as Junco, Melospiza, and Zonotrichia. Although Calcarius and Plectrophenax are often thought to be putative emberizids, all our analyses placed these genera basal to all other sparrows examined. As observed with Calcarius, Spizella did not form a monophyletic group, with S. arborea being the sister-taxon to Passerella iliaca. Our analyses also suggest that Aimophila ruficeps is probably more closely related to the "brown towhees" (Pipilo aberti, P. crissalis, and P. fuscus) than its putative congeners. The genus Ammodramus was also not monophyletic, since it appears that Passerculus sandwichensis is more closely related to A. henslowii and A. leconteii then either one is related to its congener A. savannarum. Finally, our analyses exhibited other unsuspected associations, such as the sister-taxon relationships between Amphispiza bilineata and the Chondestes grammacus/Calamospiza melanocorys clade, and Amphispiza belli and Pooecetes gramineus.
 ...
PMID:A phylogenetic analysis of the emberizid sparrows based on three mitochondrial genes. 1296 6

Regulation of expression of mitochondrial DNA- (mtDNA-) encoded genes of oxidative phosphorylation can occur rapidly in neural cells subjected to a variety of physiological and pathological conditions. However, the intracellular signal(s) involved in regulating these processes remain unknown. Using mtDNA-encoded cytochrome oxidase subunit III (COX III), we show that its mRNA expression in a differentiated rat pheochromocytoma cell line PC12S is decreased by chronic exposure to agents that increase intracellular sodium. Treatment of differentiated PC12S cells either with ouabain, an inhibitor of Na/K-ATPase, or with monensin, a sodium ionophore, decreased the steady-state levels of COX III mRNA by 50%, 3-4 h after addition of the drugs. No significant reduction in mtDNA-encoded 12S rRNA or nuclear DNA-encoded beta-actin mRNA were observed. Removal of the drugs restored the normal levels of COX III mRNA. Determination of half-lives of COX III mRNA, 12S rRNA, and beta-actin mRNA revealed a selective decrease in the half-life of COX III mRNA from 3.3 h in control cells to 1.6 h in ouabain-treated cells, and to 1 h in monensin-treated cells. These results suggest the existence of a mechanism of posttranscriptional regulation of mitochondrial gene expression that is independent of the energetic status of the cell and may operate under pathological conditions.
 ...
PMID:Chronic exposure of neural cells to elevated intracellular sodium decreases mitochondrial mRNA expression. 1612 Feb 74

The sequence of a 6.24 kb DNA segment of the mitochondrial genome from rat liver has been determined. It comprises several genes coding for mitochondrial protein subunits and five tRNA genes in the following order: cytochrome oxidase subunit I - tRNA (UCN) (Ser) -tRNA(Asp) - cytochrome oxidase subunit II - tRNALys -ATPase subunit - cytochrome oxidase subunit III -tRNA(Gly) - potential open reading frame - tRNA(Arg) -two potential open reading frames. The tRNA genes were detected by a computer search programme. The assignments for the protein coding sequences were made through comparison with known sequences, mainly from the yeast mitochondrial proteins (e.g. Bonitz et al. 1980). Our data are discussed with regard to the features of gene arrangement, codon usage, and tRNA structure in mammalian mitochondria (Anderson et al. 1981).
...
PMID:Analysis of a DNA segment from rat liver mitochondria containing the genes for the cytochrome oxidase subunits I, II and III, ATPase subunit 6, and several tRNA genes. 2418 61