Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have cloned and sequenced over 9 kb of the mitochondrial genome from the sea star Pisaster ochraceus. Within a continuous 8.0-kb fragment are located the genes for NADH dehydrogenase subunits 1, 2, 3, and 4L (ND1, ND2, ND3, and ND4L), cytochrome oxidase subunits I, II, and III (COI, COII, and COIII), and adenosine triphosphatase subunits 6 and 8 (ATPase 6 and ATPase 8). This large fragment also contains a cluster of 13 tRNA genes between ND1 and COI as well as the genes for isoleucine tRNA between ND1 and ND2, arginine tRNA between COI and ND4L, lysine tRNA between COII and ATPase 8, and the serine (UCN) tRNA between COIII and ND3. The genes for the other five tRNAs lie outside this fragment. The gene for phenylalanine tRNA is located between cytochrome b and the 12S ribosomal genes. The genes for tRNA(glu) and tRNA(thr) are 3' to 12S ribosomal gene. The tRNAs for histidine and serine (AGN) are adjacent to each other and lie between ND4 and ND5. These data confirm the novel gene order in mitochondrial DNA (mtDNA) of sea stars and delineate additional distinctions between the sea star and other mtDNA molecules.
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PMID:Nucleotide sequence of nine protein-coding genes and 22 tRNAs in the mitochondrial DNA of the sea star Pisaster ochraceus. 197 16

We report seven unrelated families with mitochondrial tRNA(Ser(UCN)) gene mutations at three different loci. A novel G7497A mutation is found in two families, both of which present with progressive myopathy, ragged-red fibers, lactic acidosis, and deficiency of respiratory chain complexes I and IV. This mutation presumably affects the tertiary tRNA(Ser(UCN)) dihydrouridine interaction. Mutations 7472 insC and T7512C, found in three and two families, respectively, are associated with myoclonus epilepsy, deafness, ataxia, cognitive impairment, and complex IV deficiency. No ragged-red fibers or ultrastructural abnormalities are seen. It is interesting that 6 of our 7 index patients are apparently homoplasmic, indicating a minor pathogenetic power of the tRNA(Ser(UCN)) mutations.
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PMID:Progressive myoclonus epilepsy and mitochondrial myopathy associated with mutations in the tRNA(Ser(UCN)) gene. 977 62

The perioculomotor region contains several functional cell groups, including parasympathetic preganglionic neurons of the ciliary ganglion, motoneurons of multiply innervated muscle fibers (MIF) of extraocular muscles, and urocortin-positive neurons. In this study, midbrain sections of monkey and human were treated with antibodies against choline acetyltransferase (ChAT), cytochrome oxidase (CytOx), nonphosphorylated neurofilaments (NP-NF), chondroitin sulfate proteoglycan (CSPG), and urocortin (UCN) to identify them by their histochemical properties. To facilitate the comparison between species, a new nomenclature was introduced (see also May et al., 2007), which designates these perioculomotor cell populations (pIII) in terms of their function and histochemical properties. The name Edinger-Westphal nucleus (EW) is kept for the cytoarchitecturally defined cell group traditionally considered as the location of preganglionic neurons of the ciliary ganglion. In monkey, the EW contains ChAT-positive presumed preganglionic neurons, and is therefore termed EW(PG), but in contrast human EW consists of noncholinergic UCN-positive neurons, and is therefore termed EW(U). In human, the presumed preganglionic neurons were found dorsal to EW(U), as an inconspicuous group of ChAT- and CytOx-positive neurons. They were interspersed with prominent CSPG-positive cells, a pattern also present in monkey. For the first time, the MIF motoneurons could be identified around the medial aspect of the human oculomotor nucleus as a group of ChAT-positive neurons that lack CSPG-positive perineuronal nets. Moreover, the Perlia nucleus was found to share the histochemical properties of oculomotor twitch motoneurons. The present results form the basis for addressing the appropriate functional cell groups in correlative clinicopathological studies.
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PMID:Perioculomotor cell groups in monkey and man defined by their histochemical and functional properties: reappraisal of the Edinger-Westphal nucleus. 1818 30

A number of nuclear and mitochondrial mutations have been implicated in non-syndromic hearing loss. Among them, various mutations of mitochondrial Ser(UCN)-tRNA and 12S rRNA genes have been found to be associated with deafness; the A7445G mitochondrial DNA (mtDNA) in this group is unique, simultaneously affecting two different mitochondrial genes, encoding the Ser(UCN)-tRNA and the first subunit of cytochrome oxidase. Besides the hearing loss, it is mainly associated with palmoplantar keratoderma, though; different phenotypic associations have been reported. The current paper reviews the available PubMed reports on the A7445G mtDNA mutation, with special attention to the phenotypic variations. Further, a Hungarian family with the A7445G mutation is reported, in which analysis of both the affected and the non-affected members revealed the mutation in both homo- and heteroplasmic forms, independently of the hearing status of the subjects, a phenomenon previously not reported in other pedigrees. The female lineage represented a rare variant of the U4b haplogroup.
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PMID:Phenotypic variants of the deafness-associated mitochondrial DNA A7445G mutation. 1853 5

Some cases of maternally inherited isolated deafness are caused by mtDNA mutations, frequently following an exposure to aminoglycosides. Two mitochondrial genes have been clearly described as being affected by mutations responsible for this pathology: the ribosomal RNA 12S gene and the transfer RNA serine (UCN) gene. A previous study identified several candidate novel mtDNA mutations, localized in a variety of mitochondrial genes, found in patients with no previous treatment with aminoglycosides. Five of these candidate mutations are characterized in the present study. These mutations are localized in subunit ND1 of complex I of the respiratory chain (m.3388C>A [p.MT-ND1:Leu28Met]), the tRNA for Isoleucine (m.4295A>G), subunit COII of complex IV (m.8078G>A [p.MT-CO2:Val165Ile]), the tRNA of Serine 2 (AGU/C) (m.12236G>A), and Cytochrome B, subunit of complex III (m.15077G>A [p.MT-CYB:Glu111Lys]). Cybrid cell lines have been constructed for each of the studied mtDNA mutations and functional studies have been performed to assess the possible consequences of these mutations on mitochondrial bioenergetics. This study shows that a variety of mitochondrial genes, including protein-coding genes, can be responsible for nonsyndromic deafness, and that exposure to aminoglycosides is not required to develop the disease, giving new insights on the molecular bases of this pathology.
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PMID:Novel mitochondrial DNA mutations responsible for maternally inherited nonsyndromic hearing loss. 2224 83