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.
 ...
PMID:Nucleotide sequence of nine protein-coding genes and 22 tRNAs in the mitochondrial DNA of the sea star Pisaster ochraceus. 197 16

Inheritance of the mitochondrial genome is known to be exclusively maternal. To determine whether the loss of paternal mitochondria could be due to a deficiency of RNA in the spermatozoal mitochondria, the expression of mitochondrial genes was studied in testicular cells at various stages of spermatogenesis and in epididymal spermatozoa. The presence of mitochondrial transcripts was examined by Northern blot analysis using probes for the following mitochondrially encoded genes: 12 S and 16 S ribosomal RNAs and a group of mRNAs including cytochrome oxidase subunits I and II (COI-COII), cytochrome b (cyt b), adenosine triphosphatase (ATPase) subunits 6 and 8, and subunit 1 of the respiratory chain NADH dehydrogenase (ND1). Comparison of total testicular RNA preparations from prepuberal (6, 8, 12, 16, 18, 20, 22, and 30 days old) and sexually mature (45 days old) mice revealed no major qualitative or quantitative differences in the levels of the mitochondrial transcripts described above. Similar results were observed from enriched preparations of type A and B spermatogonia and interstitial cells obtained from the testes of 8-day-old mice. Transcripts for COI-COII, ATPase 6, or ND1 were reduced in amount in the enriched preparations of pachytene spermatocytes, round spermatids, and residual bodies when compared to the amount in total testis or liver RNA. Transcripts of all the mitochondrial genes analyzed were present in RNA preparations isolated from sperm midpiece tails obtained after sonication of epididymal spermatozoa. These studies demonstrate that (a) during testicular development the levels of mitochondrial RNA in total testicular extracts show no major qualitative and quantitative differences; (b) the mitochondrial transcripts in enriched populations of type A and type B spermatogonia are not different from those obtained from total testes extracts; (c) mitochondrial transcript levels gradually decrease in enriched preparations of pachytene spermatocytes, round spermatids, and residual bodies; and (d) the mitochondrial rRNAs and mRNAs encoded by several mitochondrial genes can be isolated from sperm midpiece tails.
 ...
PMID:Mitochondrial gene expression in male germ cells of the mouse. 277 68

The mitochondrial DNA (mtDNA) from Paracentrotus lividus (sea urchin) eggs, a circular molecule of about 15,500 bp, has been cloned in plasmid vectors after cleavage with various restriction enzymes. By a combination of Northern blot hybridization and nucleotide sequence analysis we have characterized most of the P. lividus mitochondrial transcripts and determined the basic gene organization of the mtDNA. The nucleotide sequence of a gene for one NADH dehydrogenase (ND) subunit, ND4L, has also been determined. Our results show the existence of a novel gene order. The 12S and 16S rRNA genes are not contiguous but are separated from each other by ND1 and ND2 genes. The ND4L gene is not adjacent to ND4 but is located between the tRNAArg gene and the gene for subunit II of cytochrome oxidase (CoII). The tRNA genes are reshuffled and contrary to all vertebrate mitochondrial genomes studied so far, there are no intergenic regions between the tRNAPhe and the cytochrome b genes. These characteristics suggest a peculiar mechanism for the regulation of gene expression in this organism and provide information on the evolution of the mitochondrial genetic system in animal cells.
 ...
PMID:A novel gene order in the Paracentrotus lividus mitochondrial genome. 359 50

We have identified a point mutation at nucleotide position 3460 in the ND1 gene of complex I in a Japanese pedigree with Leber's hereditary optic neuropathy by sequencing the ND genes in mitochondrial DNA. None of the 60 healthy Japanese had the 3460 mutation. The proband and his mother also had the 7444 mutation in the COI gene of complex IV and became nearly blind at age 19 with visual acuities of 0.02 OD and 0.04 OS We screened 30 patients with bilateral optic atrophy for the 3460 mutation, and identified one male patient who had the 3460 mutation in heteroplasmic fashion without carrying the 7444 mutation. He lost his sight at age 14 but it recovered to 1.2 OD and 0.7 OS about two years and half after the onset. The difference in final visual acuity between these two patients may reflect the degree of reduction in mitochondrial energy production.
 ...
PMID:[Molecular genetic analysis of Leber's hereditary optic neuropathy with the 3460 mutation in Japanese pedigrees]. 761 Oct 10

The mitochondrial complex I genes were sequenced in seven Leber hereditary optic neuroretinopathy (LHON) families without the ND4/11,778 and ND1/3460 mutations. Four replacement mutations restricted only to LHON families were found, one in the ND1 gene at nt 4025, and three in the ND5 gene at nt 12,811, 13,637, and 13,967. The mutations did not change evolutionarily conserved amino acids suggesting that they are not primary LHON mutations in these families. They may be considered as secondary LHON mutations serving as exacerbating factors in an appropriate genetic background. A complex III mutation, cyt b/15,257, has been suggested to be one of the primary mutations causing LHON. Its presence was determined for 23 Finnish LHON families, and it was detected in two families harboring the ND4/11,778 mutation. Similarly, complex IV mutation COI/7444 was screened in Finnish LHON families, and it was found in one family carrying the ND1/3460 mutation.
 ...
PMID:The spectrum of mitochondrial DNA mutations in families with Leber hereditary optic neuroretinopathy. 790 Nov 41

A cDNA library of substantia nigra pars compacta from a patient with Parkinson's disease (PD) was differentially screened with probes of normal and parkinsonian substantia nigra enriched in neuronal transcripts. Fifty-eight clones were isolated; 39 were subunits of mitochondrial respiratory complexes I and IV. Parallel screening of a cDNA library derived from normal substantia nigra confirmed differential representation of the transcripts in the substantia nigra pars compacta. In situ hybridization in postmortem brain from parkinsonian and control subjects, with representative complex I and complex IV probes, showed increased labeling, at the cellular level, of the complex I subunit ND1 in neurons of the lateral substantia nigra, where cell death is greatest in PD, but decreased labeling in the medial substantia nigra where fewer cells die. Expression of a complex IV subunit, COXI, increased, however, in both parts of the structure. Increased expression of ND1 and COXI was also observed in nerve growth factor-differentiated PC12 cells undergoing apoptosis induced by tumor necrosis factor-alpha, suggesting that the differential regulation of certain mitochondrial mRNAs may be associated with this form of cell death. This in vitro model of apoptosis is potentially relevant to the death of dopaminergic neurons in PD, because these cells express the tumor necrosis factor-alpha receptor, and neighboring microglial cells in patients synthesize the cytokine.
 ...
PMID:Is differential regulation of mitochondrial transcripts in Parkinson's disease related to apoptosis? 910 38

In Parkinson's disease, there is a selective defect in complex I of the electron transfer chain. To better understand complex I and its involvement in neurodegenerative disease, we raised an antibody against a conserved epitope of the human mitochondrially encoded subunit 1 of complex I (ND1). Antibodies were affinity purified and assessed by ELISA, immunoblotting, and immunocytochemistry. Immunoblots of brain homogenates from mouse, rat, and monkey brain showed a single 33-kDa band consistent with the predicted molecular mass of the protein. Subcellular fractionation showed the protein to be enriched in mitochondria. Immunocytochemistry in rat brain revealed punctate labeling in cell bodies and processes of neurons. Immunoreactively generally co-localized with subunit IV of complex IV. In striatum, ND1 immunoreactively was greatly enriched in large cholinergic neurons and neurons containing nitric oxide synthase, two cell populations that are resistant to excitotoxic and metabolic insults. In substantia nigra, many dopaminergic neurons had little ND1 immunoreactivity, which may help to explain their sensitivity to complex I inhibitors. In spinal cord, ND1 immunoreactively was enriched in motor neurons. We conclude that complex I is differentially distributed across brain regions, between neurons and glia, and between types of neurons. This antibody should provide a valuable tool for assessing complex I in normal and pathological conditions.
 ...
PMID:Immunocytochemical characterization of the mitochondrially encoded ND1 subunit of complex I (NADH : ubiquinone oxidoreductase) in rat brain. 1085 84

In a 33-year-old man, mitochondriopathy was diagnosed upon short stature, auditory impairment, gynaecomastia, hypogonadism, vertical ophthalmoplegia, cerebral atrophy, leucencephalopathy, cataract, hypertrabeculated left ventricle, hypothyroidism, diabetes mellitus, glomerulonephritis necessitating kidney transplantation, general wasting, polyneuropathy, abnormally high lactate levels on exercise, partially reduced cytochrome-c oxidase staining and abnormally structured mitochondria on muscle biopsy. Mitochondrial DNA (mtDNA) analysis revealed 1 novel (A15662G) and 3 known mtDNA transition(s) (T3398C, T4216C, G15812A) affecting the cytb and ND1 gene, respectively. Three of the patient's transitions were also detected in blood leukocytes of the patient's maternal grandmother, mother and brother. Mutant mtDNA was heteroplasmic at >75% in the patient's skeletal muscle.
 ...
PMID:Complex mitochondriopathy associated with 4 mtDNA transitions. 1089 93

Mitochondria are one of the enzymatic sources of reactive oxygen species (ROS) and could also be a major target for ROS-mediated damage. We hypothesized that ROS may induce mitochondrial DNA (mtDNA) damage, which leads to defects of mtDNA-encoded gene expression and respiratory chain complex enzymes and thus may contribute to the progression of left ventricular (LV) remodeling and failure after myocardial infarction (MI). In a murine model of MI and remodeling created by the left anterior descending coronary artery ligation for 4 weeks, the LV was dilated and contractility was diminished. Hydroxyl radicals, which originated from the superoxide anion, and lipid peroxide formation in the mitochondria were both increased in the noninfarcted LV from MI mice. The mtDNA copy number relative to the nuclear gene (18S rRNA) preferentially decreased by 44% in MI by a Southern blot analysis, associated with a parallel decrease (30% to 50% of sham) in the mtDNA-encoded gene transcripts, including the subunits of complex I (ND1, 2, 3, 4, 4L, and 5), complex III (cytochrome b), complex IV (cytochrome c oxidase), and rRNA (12S and 16S). Consistent with these molecular changes, the enzymatic activity of complexes I, III, and IV decreased in MI, whereas, in contrast, complex II and citrate synthase, encoded only by nuclear DNA, both remained at normal levels. An intimate link among ROS, mtDNA damage, and defects in the electron transport function, which may lead to an additional generation of ROS, might play an important role in the development and progression of LV remodeling and failure.
 ...
PMID:Mitochondrial DNA damage and dysfunction associated with oxidative stress in failing hearts after myocardial infarction. 1124 77

Eurosta solidaginis Fitch (Diptera: Tephritidae) induces galls on two species of goldenrod, Solidago (Compositae), in the northern regions of the United States. Recent studies have demonstrated that E. solidaginis is comprised of two host races that differ in adult emergence times, mate preference, and host preference. However, it is not known how much genetic variation, if any, exists among E. solidaginis host-associated populations west of Minnesota where the two host races occur in sympatry. Sequencing analysis was used to characterize two mitochondrial gene fragments: (1) NADH1 dehydrogenase (ND1: 539 bp) and (2) cytochrome oxidase II + tRNA(Lys) + tRNA(Asp) (CO2KD: 396 bp) from sympatric, host-associated populations of E. solidaginis in North Dakota. Our results indicated that two genetically distinct lineages exist among E. solidaginis in North Dakota that correspond with host-plant association.
 ...
PMID:Mitochondrial DNA variation among host races of Eurosta solidaginis Fitch (Diptera: Tephritidae). 1241 17


1 2 3 Next >>