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

Respiratory-competent nuclear mutants have been isolated which presented a cryosensitive phenotype on a non-fermentative carbon source, due to a dysfunctioning of the mitochondrial F1-Fo ATP synthase which results from a relative defect in subunits 6 and 8 of the Fo sector. Both proteins are mtDNA-encoded, but the defect is due to the simultaneous presence of a mutation in two unlinked nuclear genes (NCA2 and NCA3, for Nuclear Control of ATPase) promoting a modification of the expression of the ATP8-ATP6 co-transcript (formerly denoted AAP1-OLI2). This co-transcript matures at a unique site to give two cotranscripts of 5.2 and 4.6 kb in length: in the mutant, the 5.2-kb co-transcript was greatly lowered. NCA3 was isolated from a wild-type yeast genomic library by genetic complementation. The level of the 5.2-kb transcript, like the synthesis of subunits 6 and 8, was partly restored in the transformed strain. A 1011-nucleotide ORF was identified that encodes an hydrophilic protein of 35417 Da. Disruption of chromosomal DNA within the reading frame promoted a dramatic decrease of the 5.2-kb mRNA but did not abolish the respiratory competence of a wild-type strain. NCA3 is located on chromosome IV and produces a single 1780-b transcript.
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PMID:NCA3, a nuclear gene involved in the mitochondrial expression of subunits 6 and 8 of the Fo-F1 ATP synthase of S. cerevisiae. 758 26

Nucleotide sequencing of a region of the hyperthermophilic archaebacterium Sulfolobus acidocaldarius allowed us to identify an open reading frame of 780 amino acids strikingly similar to a family of eukaryotic ATPases, involved in a variety of biological functions. Sequence analysis of the predicted polypeptide revealed 63 to 66% similarity with S. cerevisiae CDC 48p and its related genes in amphibians (p97ATPase) and mammals (Valosin Containing Protein, VCP), all possibly involved in the regulation of the cell cycle. The finding of an archaebacterial equivalent of these proteins with a high degree of similarity suggests that it represents the same gene in these various species. The new archaebacterial ORF, called SAV (S. acidocaldarius VCP-like) exhibited the usual signature of all members of the family, a highly conserved domain of about 200 amino acids, which is duplicated. Thus, apart from the VCP-like proteins, SAV also appeared similar, although less clearly, to other ATPases, members of the family, involved in vesicle-mediated transport (NSF, Sec18p), peroxysome assembly (PAS1p), and gene expression in yeast (SUG1p) and in human immunodeficiency virus (TBP-1). Finally, the discovery of the archaebacterial gene could enlighten not only the evolutionary relationships between the members of this complex ATPase family, but also the cellular function of these proteins, that is presently obscure.
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PMID:SAV, an archaebacterial gene with extensive homology to a family of highly conserved eukaryotic ATPases. 828 63

The complete 27,694-bp mitochondrial (mt) DNA sequence of Hansenula wingei, which is a typical budding yeast and contains circular mitochondrial DNA, has been determined. The mt sequence contains genes encoding large and small ribosomal RNAs, 25 tRNAs, three subunits of cytochrome c oxidase (subunits 1, 2 and 3), three subunits of ATPase (subunits 6, 8 and 9), apocytochrome b, seven subunits of NADH dehydrogenase (subunits 1, 2, 3, 4, 4L, 5 and 6), and a ribosomal protein, VAR1. The VAR1 gene is considered to be a typical yeast type. This is consistent with data on DNA and the deduced amino-acid sequence homology comparisons of genes ubiquitous in yeast and fungi. However, we have identified seven genes encoding NADH dehydrogenase subunits, which are not found in other yeast mitochondrial genomes, thus placing the H. wingei mitochondrial genome in a unique position. In addition the H. wingei mitochondrial genome also encodes one tRNA pseudogene and one short unidentified ORF. The genome is compact with only two introns both of which contain an ORF. One intron lies in the large rRNA gene while the other is situated in the cytochrome c oxidase subunit-1 gene. The conserved nonanucleotide motif (A/T)TATAAG (T/A)(A/T), which is a transcription start signal in Saccharomyces cerevisiae mitochondria, has also been found in the H. wingei mitochondrial genome. The codon assignments for ATA and CTN in H. wingei mitochondria are different from those in S. cerevisiae mitochondria. These results indicate a unique and novel structure for the H. wingei mitochondrial genome in terms of characteristics which are typical for both yeast and for filamentous fungi. This is the first complete mt DNA sequence report in yeast.
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PMID:The complete mitochondrial DNA sequence of Hansenula wingei reveals new characteristics of yeast mitochondria. 853 12

The first extracellular domain of the alpha-subunit of the Na+/K+-ATPase (sodium/potassium pump) is functionally important, affecting sensitivity of the enzyme to cardiac glycosides (e.g. ouabain) and being implicated in the transport of K+. This domain is also variable among mammalian isoforms of the alpha-subunit. Using PCR, we have isolated from seven insect species with contrasting physiologies a DNA fragment containing this region, in order to help determine whether tissue-specific expression might be associated with isoforms encoded by a gene family, as it is in mammals. A single sequence (with one ORF) characteristic of Na+/K+-ATPase was obtained from genomic DNA of each species. Only the fragment from Manduca sexta contained an intron, but at a location different to that found in mammals. For all Diptera so far characterized, the species phylogeny is the same as the alpha-subunit gene phylogeny (based on the sequences of the first extracellular domain and flanking transmembrane domains). The results strongly indicate a single, ouabain-sensitive isoform of the alpha-subunit of Na+/K+-ATPase is present in Diptera.
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PMID:A single isoform of the Na+/K(+)-ATPase alpha-subunit in Diptera: evidence from characterization of the first extracellular domain. 858 45

The Leuconostoc oenos plasmid p4028 was cloned in pBlueScript (SK+), and its complete nucleotide sequence was determined. The analysis of the nucleotide sequence revealed five open reading frames, all of them located on the same strand and grouped in two clusters separated by a short noncoding stretch. A similarity search against the other sequences deposited in the EMBL and GenBank databases showed that p4028 has no significant similarity with any of the sequences checked. Nevertheless, a putative ATP-binding motif was found in ORF2. A more detailed analysis of this ORF suggests that it could encode for a DNA-dependent ATPase.
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PMID:Nucleotide sequence of plasmid p4028, a cryptic plasmid from Leuconostoc oenos. 893 55

During growth and early development of Dictyostelium discoideum, the amoebae exhibit transient pH changes in their cytosol (pHi) and external medium which correlate with the extrusion of H+ from the cell by a plasma membrane pump. Moreover, the changes in pHi have been postulated to influence early prestalk/prespore differentiation during development. To learn more about the role of H+ fluxes in Dictyostelium, we cloned and analysed cDNAs of the gene patB, which appears to encode a P-type H(+)-ATPase. The patB ORF encodes a protein (termed PAT2) of 1058 amino acids with a calculated molecular mass of 117,460 Da. When aligned with other P-type ion-transport ATPases, PAT2 showed the greatest amino acid sequence identity with plasma membrane H(+)-ATPases of plants and fungi and considerably lower identity with other monovalent cation pumps and with Ca2+ pumps. Northern and Western analyses revealed that patB is expressed at very low levels in cells growing at neutral pH, but it is up-regulated rapidly and dramatically when the cells are shifted to an acidic medium. Immunofluorescence analysis indicated that PAT2 resides on the plasma membrane. When patB was disrupted by homologous recombination, the cells grew and developed normally at neutral and slightly alkaline pHs but they were unable to grow or develop at pH 5.0, and they slowly died. In growth medium at pH 6.8, patB+ and patB cells exhibited similar levels of vanadate-sensitive ATPase activity. However, when the cells were shifted to pH 5.0, this activity rapidly increased about twofold in the control cells but not in the mutant cells. Despite the lower ATPase activity in patB cells, they showed relatively normal H+ fluxes and only a slight decrease in pHi when incubated in acidic medium. Together, these results suggest that patB encodes an acid-inducible P-type H(+)-ATPase which is indispensable for the survival of Dictyostelium cells in moderately acidic external environments.
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PMID:The patB gene of Dictyostelium discoideum encodes a P-type H(+)-ATPase isoform essential for growth and development under acidic conditions. 942 12

In the yeast Saccharomyces cerevisiae, Na+ efflux is mediated by the Ena1 ATPase, and the expression of the ENA1 gene is regulated by the Ppz1 and Ppz2 Ser/Thr protein phosphatases. On the contrary, in the fission yeast Schizosaccharomyces pombe, effective output of Na+ is attributed to the H+/Na+ antiporter encoded by the sod2 gene. We have isolated a S. pombe gene (pzh1) that encodes a 515-amino-acid protein that is 78% identical, from residue 193 to the COOH terminus, to the PPZ1 and PPZ2 gene products. Bacterially expressed Pzh1p shows enzymatic characteristics virtually identical to those of recombinant Ppz1p. When expressed in high-copy number from the PPZ1 promoter, the pzh1 ORF rescues the caffeine-induced lytic defect and slightly decreases the high salt tolerance of S. cerevisiae ppz1delta mutants. Disruption of pzh1 yields viable S. pombe cells and has virtually no effect on tolerance to caffeine or osmotic stress, but it renders the cells highly tolerant to Na+ and Li+, and hypersensitive to K+. Although lack of pzh1 results in a 2-3-fold increase in sod2 mRNA, the pzh1 mutation significantly increases salt tolerance in the absence of the sod2 gene, suggesting that the phosphatase also regulates a Sod2-independent mechanism. Therefore, the finding of a PPZ-like protein phosphatase involved in the regulation of salt tolerance in fission yeast reveals unexpected aspects of cation homeostasis in this organism.
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PMID:Regulation of salt tolerance in fission yeast by a protein-phosphatase-Z-like Ser/Thr protein phosphatase. 942 1

The human mRNA 5'-capping enzyme cDNA was identified. Three highly related cDNAs, HCE1 (human mRNAcappingenzyme1), HCE1A and HCE1B , were isolated from a HeLa cDNA library. The HCE1 cDNA has the longest ORF, which can encode a 69 kDa protein. A short region of 69 bp in the 3'-half of the HCE1 ORF was missing in HCE1A and HCE1B , and, additionally, HCE1B has an early translation termination signal, which suggests that the latter two cDNAs represent alternatively spliced product. When expressed in Escherichia coli as a fusion protein with glutathione S -transferase, Hce1p displayed both mRNA 5'-triphosphatase (TPase) and mRNA 5'-guanylyltransferase (GTase) activities, and it formed a cap structure at the 5'-triphosphate end of RNA, demonstrating that it indeed specifies an active mRNA 5'-capping enzyme. The recombinant proteins derived from HCE1A and HCE1B possessed only TPase activity. When expressed from ADH1 promoter, HCE1 but not HCE1A and HCE1B complemented Saccharomyces cerevisiae CEG1 and CET1 , the genes for GTase and TPase, respectively. These results demonstrate that the N-terminal part of Hce1p is responsible for TPase activity and the C-terminal part is essential for GTase activity. In addition, the human TPase domain cannot functionally substitute for the yeast enzyme in vivo.
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PMID:Isolation and characterization of a human cDNA for mRNA 5'-capping enzyme. 951 41

The SNF2/SWI2 ATPase/helicase family comprises proteins from a variety of species, which serve a number of functions, such as transcriptional regulation, maintenance of chromosome stability during mitosis, and various types of DNA repair. Several proteins with unknown functions are also included in this family. The number of genes that belong to this family is rapidly expanding, which makes it easier to analyze the common biological functions of the family members. This study was designed to clone the SNF2/SWI2 helicase-related genes from the fission yeast Schizosaccharomyces pombe in the hope that this would help to elucidate the common functions of the proteins in this family. The hrp1+ (helicase-related gene from S. pombe) gene was initially cloned by PCR amplification using degenerate primers based on conserved SNF2 motifs within the ERCC6 gene, which encodes a protein involved in DNA excision repair. The hrp1+ ORF codes for an 1373-amino acid polypeptide with a molecular mass of 159 kDa. Like other SNF2/SWI2 family proteins, the deduced amino acid sequence of Hrp1 contains DNA-dependent ATPase/7 helicase domains, as well as a chromodomain and a DNA-binding domain. This configuration is similar to that of mCHD1 (mouse chromo-ATPase/helicase-DNA-binding protein 1), suggesting that Hrp1 is a S. pombe homolog of mCHD1, which is thought to function in altering the chromatin structure to facilitate gene expression. Northern blot analysis showed that the hrp1+ gene produces a 4.6-kb transcript, which reaches its maximal level just before the cells enter the exponential growth phase, and then decreases gradually. DNA-damaging agents, such as MMS, MNNG and UV, decrease the rate of transcription of hrp1+. Deletion of the hrp1+ gene resulted in accelerated cell growth. On the other hand, overexpression of Hrp1 caused a reduction in growth rate. These results indicate that hrp1+ may act as a negative regulator of cellular growth.
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PMID:Isolation and characterization of hrp1+, a new member of the SNF2/SWI2 gene family from the fission yeast Schizosaccharomyces pombe. 952 Feb 66

A complementary DNA for the Tobacco Budworm, Heliothis virescens, sarco(endo)plasmic reticulum-type Ca(2+)-ATPase (HVSERCA) has been cloned and sequenced. cDNA fragments of adult rabbit fast-twitch muscle Ca(2+)-ATPase (SERCA1a) were used as heterologous probes to isolate a partial cDNA clone coding for a protein with high homology to the Ca(2+)-ATPase from Drosophila melanogaster (DRSERCA) and vertebrate ER/SR Ca2+ pumps. The entire cDNA clone contains an ORF encoding a protein of 1000 amino acids which shares the characteristic motifs of a P-type ATPase. HVSERCA shares 89% identity with DRSERCA, 80% identity with the Artemia Ca(2+)-ATPase and 72% identity with avian and mammalian SERCAs. An insect Ca(2+)-ATPase-specific polyclonal antiserum has been raised against a fusion protein containing sequence from the cytoplasmic domain of HVSERCA. Heterologous expression of the insect pump in COS-7 cells has been demonstrated by immunocytochemistry and the reticular pattern of staining is consistent with an ER localisation. However, the expressed enzyme from COS-7 cells does not appear to be active.
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PMID:Cloning and expression of an insect Ca(2+)-ATPase from Heliothis virescens. 952 69


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