Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.3.14 (ATP synthase)
 7,042 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of the histidyl residue at position 49 (H49) of the bovine mitochondrial F1-ATPase inhibitor protein (F1I) was examined by site-directed mutagenesis. Six amino acids (Q, E, K, V, L, and I) were substituted for H49 and the activities of the resulting inhibitor proteins were characterized with respect to pH. Each of the six mutations abolished the pH sensitivity which is characteristic of wild-type F1I. At pH 8.0 each of the mutations caused an increase in apparent maximum inhibition and a decrease in apparent Ki relative to wild type. At pH 6.7 the hydrophilic substitutions had little effect on apparent Ki, while the hydrophobic substitutions caused increases of 3.5- to 8.5-fold relative to wild type. The ratios of apparent Ki at pH 8.0 to apparent Ki at pH 6.7 were in the range of 0.5 to 1.6 for the mutants, whereas the wild-type value is 15.0. The mutations appear to shift the equilibrium between active and inactive conformations of F1I toward the active state. We find that H49 is required by F1I for sensitivity to pH and that it may facilitate the transition between active and inactive states of F1I. A possible role for H49 in the stabilization of the inactive state through participation in a multivalent complex with Zn2+ is also discussed.
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PMID:Histidine-49 is necessary for the pH-dependent transition between active and inactive states of the bovine F1-ATPase inhibitor protein. 859 69

Saccharomyces cerevisiae mitochondria have a polyphosphatase activity which is insensitive to a number of inhibitors of mitochondrial ATPase and pyrophosphatase (PPase). Heparin (20 micrograms/ml) and EDTA (0.5 mM) do not inhibit ATPase and PPase activities but completely suppressed mitochondrial polyphosphatase activity. The mitochondrial polyphosphatase activity is maximal at neutral pH; it is inhibited by monovalent cations in the presence of Tris+ (K+ > Na+ > NH4+), and stimulated by bivalent metal cations (Co2+ > Mg2+ > Zn2+ > Mn2+). The polyphosphatase activity does not significantly depend on polyphosphate chain length from 9 to 208 but is more than one order of magnitude higher than activity with tripolyphosphate. Some properties of mitochondrial polyphosphatase activity differ from the characteristics of polyphosphatases of cell envelope, cytosol, vacuoles and nuclei of the same S. cerevisiae strain.
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PMID:[Characteristics of polyphosphatase activity of isolated mitochondria from Saccharomyces cerevisiae]. 899 89

Loss of the mitochondrial genome (rho(0) cell) or elimination of the mitochondrial inner membrane protein Oxa1p causes a dramatic increase in expression of the ATP binding cassette transporter-encoding gene PDR5 in the yeast Saccharomyces cerevisiae. This increase in gene expression occurs via activation of the function of the Cys(6)-Zn(II)(2) cluster transcription factor Pdr3p, which in turn autoregulates expression of its structural gene. Surprisingly, the acquisition of PDR5-dependent multidrug resistance occurs at a very high frequency, consistent with the appearance of rho(-) cells in a fermentatively growing culture (approximately 2%). The degree of activation of Pdr3p target genes was found to vary considerably and to be influenced by the presence of the homologous protein, Pdr1p. Mutagenesis and overexpression studies provided evidence that the control of Pdr3p expression was the major control point of this transcription factor by mitochondrial retrograde signaling. Because both rho(0) and oxa1 mutant cells have multiple defects including loss of normal respiratory chain function and oxidative phosphorylation, a series of mutant strains with more selective defects in mitochondrial function was employed to identify the molecular signal that triggers PDR5 transcriptional activation. Only mutations that influenced the functional status of the F(0) subunit of the mitochondrial ATPase were found to lead to activation of PDR5 expression.
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PMID:Saccharomyces cerevisiae multidrug resistance gene expression inversely correlates with the status of the F(0) component of the mitochondrial ATPase. 1160 84

Most of the nuclear encoded mitochondrial precursor proteins contain an N-terminal extension called the presequence that carries targeting information and that is cleaved off after import into mitochondria. The presequences are amphiphilic, positively charged, membrane-interacting peptides with a propensity to form alpha-helices. Here we have investigated the proteolysis of the presequences that have been cleaved off inside mitochondria. A presequence derived from the overexpressed F(1)beta subunit of the ATP synthase and specific synthetic fluorescent peptides (Pep Tag Protease assay) have been shown to undergo rapid degradation catalyzed by a matrix located protease. We have developed a three-step chromatographic procedure including affinity and anion exchange chromatography for isolation of the protease from potato tuber mitochondria. Two-dimensional gel electrophoresis of the isolated proteolytically active fraction followed by electrospray ionization-mass spectrometry/mass spectrometry and data base searches allowed identification of the presequence peptide-degrading protease in Arabidopsis thaliana data base as a novel mitochondrial metalloendoprotease with a molecular mass of 105 kDa. The identified metalloprotease contains an inverted zinc-binding motif and belongs to the pitrilysin family.
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PMID:Isolation and identification of a novel mitochondrial metalloprotease (PreP) that degrades targeting presequences in plants. 1213 66

The biophysical and biochemical properties of motor proteins have been well-studied, but these motors also show promise as mechanical components in hybrid nano-engineered systems. The cytoplasmic F(1) fragment of the adenosine triphosphate synthase (F1-ATPase) can function as an ATP-fuelled rotary motor and has been integrated into self-assembled nanomechanical systems as a mechanical actuator. Here we present the rational design, construction and analysis of a mutant F1-ATPase motor containing a metal-binding site that functions as a zinc-dependent, reversible on/off switch. Repeated cycles of zinc addition and removal by chelation result in inhibition and restoration, respectively, of both ATP hydrolysis and motor rotation of the mutant, but not of the wild-type F1 fragment. These results demonstrate the ability to engineer chemical regulation into a biomolecular motor and represent a critical step towards controlling integrated nanomechanical devices at the single-molecule level.
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PMID:Control of a biomolecular motor-powered nanodevice with an engineered chemical switch. 1261 6

Anthrax toxin produced by Bacillus anthracis is a tripartite toxin comprising of protective antigen (PA), lethal factor (LF) and edema factor (EF). PA is the receptor-binding component, which facilitates the entry of LF or EF into the cytosol. EF is a calmodulin-dependent adenylate cyclase that causes edema whereas LF is a zinc metalloprotease and leads to necrosis of macrophages. It is also important to note that the exact mechanism of LF action is still unclear. With this view in mind, in the present study, we investigated a proteome wide effect of anthrax lethal toxin (LT) on mouse macrophage cells (J774A.1). Proteome analysis of LT-treated and control macrophages revealed 41 differentially expressed protein spots, among which phosphoglycerate kinase I, enolase I, ATP synthase (beta subunit), tubulin beta2, gamma-actin, Hsp70, 14-3-3 zeta protein and tyrosine/tryptophan-3-monooxygenase were found to be down-regulated, while T-complex protein-1, vimentin, ERp29 and GRP78 were found to be up-regulated in the LT-treated macrophages. Analysis of up- and down-regulated proteins revealed that primarily the stress response and energy generation proteins play an important role in the LT-mediated macrophage cell death.
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PMID:Proteome analysis of mouse macrophages treated with anthrax lethal toxin. 1569 49

Bovine factor B, a polypeptide required for the coupled activity of the mitochondrial ATP synthase complex, was cloned. A novel expression system for overproducing the recombinant bovine factor B was developed, which yielded the recombinant polypeptide at a level of 12-15 mg of protein per liter of bacterial culture. Reconstitution of the recombinant polypeptide with factor B-depleted ammonia, EDTA-treated submitochondrial particles (AE-SMP) restored the formation of substrate-driven DeltapH gradient across vesicular membranes, presumably by blocking a proton leak. The proton leak in the AE-SMP could also be blocked by the F0 inhibitors oligomycin and dicyclohexylcarbodiimide, but not the F1-ATPase inhibitors efrapeptin and aurovertin B. The six factor B thiols titrated rapidly with Ellman's reagent, and two of these, presumably Cys92 and Cys94, gained protection following treatment of factor B with a vicinal dithiol-specific reagent phenylarsine oxide (PAO). Similarly, Cd2+, whose binding to factor B is believed to also involve a vicinal dithiol, and PAO, protected approximately 2 Cys residues against labeling with sulfhydryl-specific fluorescent reagent fluorescein-5'-maleimide. The circular dichroism spectra showed that binding of Cd2+ and Zn2+, but not Ca2+ to bovine factor B caused small but reproducible changes in the secondary structure elements of the polypeptide.
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PMID:Bovine factor B: cloning, expression, and characterization. 1657 55

The Golgi-localized Ca2+- and Mn2+-transporting ATPase Pmr1 is important for secretory pathway functions. Yeast mutants lacking Pmr1 show growth sensitivity to multiple drugs (amiodarone, wortmannin, sulfometuron methyl, and tunicamycin) and ions (Mn2+ and Ca2+). To find components that function within the same or parallel cellular pathways as Pmr1, we identified genes that shared multiple pmr1 phenotypes. These genes were enriched in functional categories of cellular transport and interaction with cellular environment, and predominantly localize to the endomembrane system. The vacuolar-type H+-transporting ATPase (V-ATPase), rather than other Ca2+ transporters, was found to most closely phenocopy pmr1Delta, including a shared sensitivity to Zn2+ and calcofluor white. However, we show that pmr1Delta mutants maintain normal vacuolar and prevacuolar pH and that the two transporters do not directly influence each other's activity. Together with a synthetic fitness defect of pmr1DeltavmaDelta double mutants, this suggests that Pmr1 and V-ATPase work in parallel toward a common function. Overlaying data sets of growth sensitivities with functional screens (carboxypeptidase secretion and Alcian Blue binding) revealed a common set of genes relating to Golgi function. We conclude that overlapping phenotypes with Pmr1 reveal Golgi-localized functions of the V-ATPase and emphasize the importance of calcium and proton transport in secretory/prevacuolar traffic.
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PMID:A phenomics approach in yeast links proton and calcium pump function in the Golgi. 1731 95

A 2-D reference map in pI range 3-10 was constructed for the soluble protein fraction of Phanerochaete chrysosporium growing vegetatively under standard conditions. Functional annotation could be made for 517 spots out of 720 that were subjected to MALDI-TOF-MS analysis, according to the specific accession numbers from the P. chrysosporium genomic database. Further analysis of the data revealed 314 distinct ORFs, 118 of which yielded multiple spots on the master gel. Functional classification of the proteins was made according to the eukaryote orthologous groups defined in the organism's genome website. The functional class of PTMs, protein turnover and chaperones was represented with the highest number (63) of the identified ORFs. Six proteins were assigned to the hypothetical proteins and 29 were predicted to have a signal peptide sequence. Subcellular localization predictions were also made for the identified proteins. Of the protein spots detected on the master gel, 380 were found to be probably phosphorylated and 96 of these matched to the identified proteins. The reference map was efficiently used in the identification of the proteins differentially expressed under cadmium and copper stress. Three new ribosomal proteins as well as zinc-containing alcohol dehydrogenase, glucose-6-phosphate isomerase, flavonol/cinnamoyl-CoA reductase, H+-transporting two-sector ATPase, ribosomal protein S7, ribosomal protein S21e, elongation factor EF-1 alpha subunit were demonstrated as the most strongly induced.
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PMID:Phanerochaete chrysosporium soluble proteome as a prelude for the analysis of heavy metal stress response. 1736 74

OPA1, an intra-mitochondrial dynamin GTPase, is a key actor of outer and inner mitochondrial membrane dynamic. OPA1 amino-terminal cleavage by PARL and m-AAA proteases was recently proposed to participate to the mitochondrial network dynamic in a DeltaPsi(m)-dependent way, and to apoptosis. Here, by an in vitro approach combining the use of purified mitochondrial fractions and mitochondrial targeting drugs, we intended to identify the central stimulus responsible for OPA1 cleavage. We confirm that apoptosis induction and PTPore opening, as well as DeltaPsi(m) dissipation induce OPA1 cleavage. Nevertheless, our experiments evidenced that decreased mitochondrial ATP levels, either generated by apoptosis induction, DeltaPsi(m) dissipation or inhibition of ATP synthase, is the common and crucial stimulus that controls OPA1 processing. In addition, we report that ectopic iron addition activates OPA1 cleavage, whereas zinc inhibits this process. These results suggest that the ATP-dependent OPA1 processing plays a central role in correlating the energetic metabolism to mitochondrial dynamic and might be involved in the pathophysiology of diseases associated to excess of iron or depletion of zinc and ATP.
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PMID:OPA1 cleavage depends on decreased mitochondrial ATP level and bivalent metals. 1782 66


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