Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 24
Filter
1.
Clin Psychol Rev ; 100: 102236, 2023 03.
Article in English | MEDLINE | ID: mdl-36587461

ABSTRACT

OBJECTIVES: We re-analysed data from published meta-analyses testing the effects of Transcranial Magnetic Stimulation (TMS) on Major Depressive Disorder (MDD) in adults. We applied up-to-date meta-analytic techniques for handling heterogeneity including the random-effects Hartung-Knapp-Sidik-Jonkman method and estimated 95% prediction intervals. Heterogeneity practices in published meta-analyses were assessed as a secondary aim. STUDY DESIGN AND SETTING: We performed systematic searches of systematic reviews with meta-analyses that included randomised controlled trials assessing the efficacy, tolerability, and side effects of TMS on MDD. We performed risk of bias assessment using A MeaSurement Tool to Assess Reviews (AMSTAR) 2 and re-analysed meta-analyses involving 10 or more primary studies. RESULTS: We included 29 systematic reviews and re-analysed 15 meta-analyses. Authors of all meta-analyses interpreted findings to suggest TMS is safe and effective for MDD. Our re-analysis showed that in 14 out of 15 meta-analyses, the 95% prediction intervals included the null and captured values in the opposite effect direction. We also detected presence of small-study effects in some meta-analyses and 24 out of 25 systematic reviews received an AMSTAR 2 rating classed as critically low. CONCLUSION: Authors of all included meta-analyses interpreted findings to suggest TMS is safe and effective for MDD despite lack of comprehensive investigation of heterogeneity. Our re-analysis revealed the direction and magnitude of treatment effects vary widely across different settings. We also found high risk of bias in the majority of included systematic reviews and presence of small-study effects in some meta-analyses. Because of these reasons, we argue TMS for MDD may not be as effective and potentially less tolerated in some populations than current evidence suggests.


Subject(s)
Depressive Disorder, Major , Adult , Humans , Randomized Controlled Trials as Topic , Transcranial Magnetic Stimulation/adverse effects , Transcranial Magnetic Stimulation/methods , Meta-Analysis as Topic
2.
Rechtsmedizin (Berl) ; 31(6): 509-519, 2021.
Article in German | MEDLINE | ID: mdl-33716407

ABSTRACT

BACKGROUND AND AIM OF THE STUDY: In Germany, a constant demographic change is taking place, which leads to an increasing aging of the society. The present study aimed to analyze natural deaths occurring at an age of ≥ 65 years, since health vulnerability in this age group is gaining importance. MATERIAL AND METHODS: Autopsy reports of the Institute of Forensic Medicine, University Hospital of the Goethe University Frankfurt/Main, Germany, were retrospectively evaluated regarding natural death cases of ≥ 65-year-olds in a time comparison (period I: 2000-2002; period II: 2013-2015). RESULTS: During both periods, a total of 1206 autopsies concerning this age group were performed. Among these, 404 cases (33.5%) of unnatural death and 39 cases (3.2%) of a combination of natural and unnatural death were recorded; in 94 cases (7.8%), the manner of death could not be elucidated. The majority (n = 669; 55.5%) included cases of natural death. In the largest group of these (n = 350; 52.3%), cardiac causes of death were predominant, followed by 132 (19.7%) respiratory and 47 (7.0%) abdominal causes of death. In addition, 37 (5.5%) cases of malignant neoplasms, 33 (4.9%) of ruptures of large vessels, 33 (4.9%) of cerebral, and 37 (5.5%) other cases of natural death were noted. A significant decrease of cardiac causes of death was observed in the comparison of periods I and II. In particular, there was a significant decrease in high-grade occlusive coronary sclerosis. Moreover, there were significant differences between both sexes. Men had significantly more bypasses, stents and heart scars and suffered a myocardial infarction about 10 years earlier than women. CONCLUSION: The results of the present study are largely consistent with the literature. The decrease in numbers of cardiac deaths may be attributed to increasingly better medical care and to a significantly higher rate of stent implantation. Especially in times of pandemics, the role of forensic gerontology will become more important.

3.
J Cyst Fibros ; 19(2): 299-304, 2020 03.
Article in English | MEDLINE | ID: mdl-31501052

ABSTRACT

BACKGROUND: POL6014 is a novel, orally inhaled neutrophil elastase (NE) inhibitor in development for cystic fibrosis (CF). METHODS: Two studies, one in healthy volunteers (HVs, doses 20 to 960 mg) and one in subjects with CF (doses 80 to 320 mg) were conducted to evaluate the safety, tolerability and pharmacokinetics (PK) of single ascending doses of inhaled POL6014 with a Pari eFlow® nebuliser. PK was evaluated over a period of 24 h. In addition, NE activity in CF sputum was measured. RESULTS: After single doses, POL6014 was safe and well tolerated up to 480 mg in HVs and at all doses in subjects with CF. POL6014 showed a dose-linear PK profile in both populations with Cmax between 0.2 and 2.5 µM in HVs and between 0.2 and 0.5 µM in subjects with CF. Tmax was reached at approximately 2-3 h. Mean POL6014 levels in CF sputum rapidly reached 1000 µM and were still above 10 µM at 24 h. >1-log reduction of active NE was observed at 3 h after dosing. CONCLUSION: Inhalation of POL6014 can safely lead to high concentrations within the lung and simultaneously low plasma concentrations, allowing for a clear inhibition of NE in the sputum of subjects with CF after single dosing. TRIAL REGISTRATION: European Medicines Agency EudraCT-Nr. 2015-001618-83 and 2016-000493-38.


Subject(s)
Cystic Fibrosis , Enzyme Inhibitors , Leukocyte Elastase/antagonists & inhibitors , Macrocyclic Compounds , Sputum/enzymology , Administration, Inhalation , Adult , Cystic Fibrosis/diagnosis , Cystic Fibrosis/drug therapy , Cystic Fibrosis/physiopathology , Dose-Response Relationship, Drug , Double-Blind Method , Enzyme Assays/methods , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/adverse effects , Enzyme Inhibitors/pharmacokinetics , Female , Healthy Volunteers , Humans , Lung/metabolism , Lung/physiopathology , Macrocyclic Compounds/administration & dosage , Macrocyclic Compounds/adverse effects , Macrocyclic Compounds/pharmacokinetics , Male , Nebulizers and Vaporizers
4.
Article in English | MEDLINE | ID: mdl-30642931

ABSTRACT

Murepavadin (POL7080) represents the first member of a novel class of outer membrane protein-targeting antibiotics. It specifically interacts with LptD and inhibits lipopolysaccharide (LPS) transport. Murepavadin is being developed for the treatment of serious infections by Pseudomonas aeruginosa We determined the plasma protein binding and the pharmacokinetics of murepavadin in plasma and epithelial lining fluid (ELF; pulmonary) in infected animals, and we determined the exposure-response relationship. Treatment of CD-1 neutropenic mice was started 2 h after infection using murepavadin at different dosing frequencies for 24 h, and the number of CFU per lung was determined. The sigmoid maximum-effect model was used to fit the dose-response, and the pharmacodynamic index (PDI) response was used to determine the PDI values, resulting in a static effect and 1-log kill reduction. Using R2 as an indicator of the best fit, the area under the concentration-time curve for the unbound fraction of the drug (fAUC)/MIC ratio correlated best with efficacy. The mean AUC required to provide a static effect was 36.83 mg h/liter (fAUC = 8.25 mg h/liter), and that to provide a 1-log reduction was 44.0 mg h/liter (fAUC = 9.86 mg h/liter). The mean static fAUC/MIC was determined to be 27.78, and that for a 1-log reduction was 39.85. These data may serve to determine doses in humans that are likely to be efficacious.


Subject(s)
Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/pharmacokinetics , Neutropenia/drug therapy , Peptides, Cyclic/pharmacology , Peptides, Cyclic/pharmacokinetics , Pseudomonas Infections/drug therapy , Animals , Area Under Curve , Bacterial Outer Membrane Proteins/antagonists & inhibitors , Cross Infection/drug therapy , Cross Infection/prevention & control , Disease Models, Animal , Mice , Microbial Sensitivity Tests , Neutropenia/microbiology , Pseudomonas aeruginosa/drug effects
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 131: 696-701, 2014 Oct 15.
Article in English | MEDLINE | ID: mdl-24913565

ABSTRACT

The study deals with the XPS, Raman and EDX characterization of a series of structured catalysts composed of cobalt oxides promoted by palladium and cerium oxides. The aim of the work was to relate the information gathered from spectroscopic analyses with the ones from kinetic tests of methane combustion to establish the basic structure-activity relationships for the catalysts studied. The most active catalyst was the cobalt oxide doped with little amount of palladium and wins a confrontation with pure palladium oxide catalyst which is commercially used in converters for methane. The analyses Raman and XPS analyses showed that this catalyst is composed of a cobalt spinel and palladium oxide. The quantitative approach to the composition of the catalysts by XPS and EDX methods revealed that the surface of palladium doped cobalt catalyst is enriched with palladium oxide which provides a great number of active centres for methane combustion indicated by kinetic parameters.


Subject(s)
Cerium/chemistry , Cobalt/chemistry , Methane/chemistry , Oxides/chemistry , Palladium/chemistry , Catalysis , Photoelectron Spectroscopy , Spectrometry, X-Ray Emission , Spectrum Analysis, Raman
8.
Yeast ; 16(3): 241-53, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10649453

ABSTRACT

As part of EUROFAN (European Functional Analysis Network), we investigated 21 novel yeast open reading frames (ORFs) by growth and sporulation tests of deletion mutants. Two genes (YNL026w and YNL075w) are essential for mitotic growth and three deletion strains (ynl080c, ynl081c and ynl225c) grew with reduced rates. Two genes (YNL223w and YNL225c) were identified to be required for sporulation. In addition we also performed green fluorescent protein (GFP) tagging for localization studies. GFP labelling indicated the spindle pole body (Ynl225c-GFP) and the nucleus (Ynl075w-GFP) as the sites of action of two proteins. Ynl080c-GFP and Ynl081c-GFP fluorescence was visible in dot-shaped and elongated structures, whereas the Ynl022c-GFP signal was always found as one spot per cell, usually in the vicinity of nuclear DNA. The remaining C-terminal GFP fusions did not produce a clearly identifiable fluorescence signal. For 10 ORFs we constructed 5'-GFP fusions that were expressed from the regulatable GAL1 promoter. In all cases we observed GFP fluorescence upon induction but the localization of the fusion proteins remained difficult to determine. GFP-Ynl020c and GFP-Ynl034w strains grew only poorly on galactose, indicating a toxic effect of the overexpressed fusion proteins. In summary, we obtained a discernible GFP localization pattern in five of 20 strains investigated (25%). A deletion phenotype was observed in seven of 21 (33%) and an overexpression phenotype in two of 10 (20%) cases.


Subject(s)
Gene Deletion , Genes, Fungal , Luminescent Proteins/metabolism , Open Reading Frames/genetics , Saccharomyces cerevisiae/genetics , Green Fluorescent Proteins , Luminescent Proteins/genetics , Phenotype , Recombinant Fusion Proteins/metabolism , Saccharomyces cerevisiae/classification , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae/physiology , Spores, Fungal
9.
Yeast ; 14(10): 943-51, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9717240

ABSTRACT

We describe a straightforward PCR-based approach to the deletion, tagging, and overexpression of genes in their normal chromosomal locations in the fission yeast Schizosaccharomyces pombe. Using this approach and the S. pombe ura4+ gene as a marker, nine genes were deleted with efficiencies of homologous integration ranging from 6 to 63%. We also constructed a series of plasmids containing the kanMX6 module, which allows selection of G418-resistant cells and thus provides a new heterologous marker for use in S. pombe. The modular nature of these constructs allows a small number of PCR primers to be used for a wide variety of gene manipulations, including deletion, overexpression (using the regulatable nmt1 promoter), C- or N-terminal protein tagging (with HA, Myc, GST, or GFP), and partial C- or N-terminal deletions with or without tagging. Nine genes were manipulated using these kanMX6 constructs as templates for PCR. The PCR primers included 60 to 80 bp of flanking sequences homologous to target sequences in the genome. Transformants were screened for homologous integration by PCR. In most cases, the efficiency of homologous integration was > or = 50%, and the lowest efficiency encountered was 17%. The methodology and constructs described here should greatly facilitate analysis of gene function in S. pombe.


Subject(s)
Gene Targeting/methods , Polymerase Chain Reaction , Schizosaccharomyces/genetics , Drug Resistance, Microbial/genetics , Gene Deletion , Gene Expression , Genetic Markers , Gentamicins/pharmacology , Plasmids , Recombination, Genetic , Transformation, Genetic
10.
Yeast ; 14(10): 953-61, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9717241

ABSTRACT

An important recent advance in the functional analysis of Saccharomyces cerevisiae genes is the development of the one-step PCR-mediated technique for deletion and modification of chromosomal genes. This method allows very rapid gene manipulations without requiring plasmid clones of the gene of interest. We describe here a new set of plasmids that serve as templates for the PCR synthesis of fragments that allow a variety of gene modifications. Using as selectable marker the S. cerevisiae TRP1 gene or modules containing the heterologous Schizosaccharomyces pombe his5+ or Escherichia coli kan(r) gene, these plasmids allow gene deletion, gene overexpression (using the regulatable GAL1 promoter), C- or N-terminal protein tagging [with GFP(S65T), GST, or the 3HA or 13Myc epitope], and partial N- or C-terminal deletions (with or without concomitant protein tagging). Because of the modular nature of the plasmids, they allow efficient and economical use of a small number of PCR primers for a wide variety of gene manipulations. Thus, these plasmids should further facilitate the rapid analysis of gene function in S. cerevisiae.


Subject(s)
Molecular Biology/methods , Plasmids , Polymerase Chain Reaction , Saccharomyces cerevisiae/genetics , DNA Primers , Gene Deletion , Gene Expression , Genetic Vectors , Green Fluorescent Proteins , Luminescent Proteins , Recombinant Fusion Proteins , Reproducibility of Results , Transformation, Genetic
11.
Mol Biol Cell ; 9(5): 977-91, 1998 May.
Article in English | MEDLINE | ID: mdl-9571234

ABSTRACT

Cnm67p, a novel yeast protein, localizes to the microtubule organizing center, the spindle pole body (SPB). Deletion of CNM67 (YNL225c) frequently results in spindle misorientation and impaired nuclear migration, leading to the generation of bi- and multinucleated cells (40%). Electron microscopy indicated that CNM67 is required for proper formation of the SPB outer plaque, a structure that nucleates cytoplasmic (astral) microtubules. Interestingly, cytoplasmic microtubules that are essential for spindle orientation and nuclear migration are still present in cnm67Delta1 cells that lack a detectable outer plaque. These microtubules are attached to the SPB half- bridge throughout the cell cycle. This interaction presumably allows for low-efficiency nuclear migration and thus provides a rescue mechanism in the absence of a functional outer plaque. Although CNM67 is not strictly required for mitosis, it is essential for sporulation. Time-lapse microscopy of cnm67Delta1 cells with green fluorescent protein (GFP)-labeled nuclei indicated that CNM67 is dispensable for nuclear migration (congression) and nuclear fusion during conjugation. This is in agreement with previous data, indicating that cytoplasmic microtubules are organized by the half-bridge during mating.


Subject(s)
Cell Nucleus/physiology , Microtubules/physiology , Saccharomyces cerevisiae/physiology , Spindle Apparatus/physiology , Benomyl/pharmacology , Cytoskeleton , Fungal Proteins/genetics , Fungal Proteins/metabolism , Fungal Proteins/physiology , Fungicides, Industrial/pharmacology , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolism , Microtubule-Associated Proteins/physiology , Microtubules/metabolism , Microtubules/ultrastructure , Mutagenesis , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/ultrastructure , Spindle Apparatus/metabolism , Spindle Apparatus/ultrastructure , Spores, Fungal
12.
Yeast ; 13(11): 1065-75, 1997 Sep 15.
Article in English | MEDLINE | ID: mdl-9290211

ABSTRACT

We have fused the open reading frames of his3-complementing genes from Saccharomyces kluyveri and Schizosac-charomyces pombe to the strong TEF gene promotor of the filamentous fungus Ashbya gossypii. Both chimeric modules and the cognate S. kluyveri HIS3 gene were tested in transformations of his3 S. cerevisiae strains using PCR fragments flanked by 40 bp target guide sequences. The 1.4 kb chimeric Sz. pombe module (HIS3MX6) performed best. With less than 5% incorrectly targeted transformants, it functions as reliably as the widely used geniticin resistance marker kanMX. The rare false-positive His+ transformants seem to be due to non-homologous recombination rather than to gene conversion of the mutated endogenous his3 allele. We also cloned the green fluorescent protein gene from Aequorea victoria into our pFA-plasmids with HIS3MX6 and kanMX markers. The 0.9 kb GFP reporters consist of wild-type GFP or GFP-S65T coding sequences, lacking the ATG, fused to the S. cerevisiae ADH1 terminator. PCR-synthesized 2.4 kb-long double modules flanked by 40-45 bp-long guide sequences were successfully targeted to the carboxy-terminus of a number of S. cerevisiae genes. We could estimate that only about 10% of the transformants carried inactivating mutations in the GFP reporter.


Subject(s)
Cell Cycle Proteins/genetics , Luminescent Proteins/genetics , Polymerase Chain Reaction/methods , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/genetics , Transcription Factors/genetics , Acyltransferases/genetics , Chromosome Mapping , Cloning, Molecular , Genes, Reporter , Genetic Complementation Test , Gentamicins , Green Fluorescent Proteins , Open Reading Frames , Peptide Elongation Factor 1 , Peptide Elongation Factors/genetics , Plasmids/genetics , Promoter Regions, Genetic , Recombination, Genetic , Saccharomyces/genetics , Schizosaccharomyces/genetics
13.
Yeast ; 12(13): 1315-20, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8923736

ABSTRACT

In Saccharomyces cerevisiae, most of the LYS structural genes have been identified except the genes encoding homocitrate synthase and alpha-aminoadipate aminotransferase. Expression of several LYS genes responds to an induction mechanism mediated by the product of LYS14 and an intermediate of the pathway, alpha-aminoadipate semialdehyde (alpha AASA) as an inducer. This activation is modulated by the presence of lysine in the growth medium leading to an apparent repression. Since the first enzyme of the pathway, homocitrate synthase, is feedback inhibited by lysine, it could be a major element in the control of alpha AASA supply. During the sequencing of chromosome IV of S. cerevisiae, the sequence of ORF D1298 showing a significant similarity with the nifV gene of Azotobacter vinelandii was reported. Disruption and overexpression of ORF D1298 demonstrate that this gene, named LYS20, encodes a homocitrate synthase. The disrupted segregants are able to grow on minimal medium and exhibit reduced but significant homocitrate synthase indicating that this activity is catalysed by at least two isoenzymes. We have also shown that the product of LYS20 is responsible for the greater part of the lysine production. The different isoforms are sensitive to inhibition by lysine but only the expression of LYS20 is strongly repressed by lysine. The N-terminal end of homocitrate synthase isoform coded by LYS20 contains no typical mitochondrial targeting sequence, suggesting that this enzyme is not located in the mitochondria.


Subject(s)
Isoenzymes/genetics , Oxo-Acid-Lyases/genetics , Saccharomyces cerevisiae/genetics , Amino Acids/metabolism , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Fungal , Isoenzymes/metabolism , Lysine/pharmacology , Open Reading Frames , Oxo-Acid-Lyases/metabolism , Plasmids , Polymerase Chain Reaction , Saccharomyces cerevisiae/metabolism , Sequence Homology, Nucleic Acid
14.
Proc Natl Acad Sci U S A ; 93(14): 7160-5, 1996 Jul 09.
Article in English | MEDLINE | ID: mdl-8692962

ABSTRACT

The core oligosaccharide Glc3Man9GlcNAc2 is assembled at the membrane of the endoplasmic reticulum on the lipid carrier dolichyl pyrophosphate and transferred to selected asparagine residues of nascent polypeptide chains. This transfer is catalyzed by the oligosaccharyl transferase complex. Based on the synthetic phenotype of the oligosaccharyl transferase mutation wbp1 in combination with a deficiency in the assembly pathway of the oligosaccharide in Saccharomyces cerevisiae, we have identified the novel ALG9 gene. We conclude that this locus encodes a putative mannosyl transferase because deletion of the gene led to accumulation of lipid-linked Man6GlcNAc2 in vivo and to hypoglycosylation of secreted proteins. Using an approach combining genetic and biochemical techniques, we show that the assembly of the lipid-linked core oligosaccharide in the lumen of the endoplasmic reticulum occurs in a stepwise fashion.


Subject(s)
Genes, Fungal , Lipopolysaccharides/biosynthesis , Mannosyltransferases/genetics , Mannosyltransferases/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Amino Acid Sequence , Animals , Base Sequence , Caenorhabditis elegans/genetics , Carbohydrate Sequence , DNA Primers , Genotype , Glycosylation , Lipopolysaccharides/chemistry , Lipopolysaccharides/isolation & purification , Mannosyltransferases/chemistry , Molecular Sequence Data , Mutagenesis , Polymerase Chain Reaction , Saccharomyces cerevisiae/growth & development , Sequence Homology, Amino Acid
15.
Yeast ; 12(3): 259-65, 1996 Mar 15.
Article in English | MEDLINE | ID: mdl-8904338

ABSTRACT

A PCR-method for fast production of disruption cassettes is introduced, that allows the addition of long flanking homology regions of several hundred base pairs (LFH-PCR) to a marker module. Such a disruption cassette was made by linking two PCR fragments produced from genomic DNA to kanMX6, a modification of dominant resistance marker making S. cerevisiae resistant to geneticin (G418). In a first step, two several hundred base pairs long DNA fragments from the 5'- and 3'- region of a S. cerevisiae gene were amplified in such a way that 26 base pairs extensions homologous to the kanMX6 marker were added to one of their end. In a second step, one strand of each of these molecules then served as a long primer in a PCR using kanMX6 as template. When such a LFH-PCR-generated disruption cassette was used instead of a PCR-made disruption cassette flanked by short homology regions, transformation efficiencies were increased by at least a factor of thirty. This modification will therefore also help to apply PCR-mediated gene manipulations to strains with decreased transformability and/or unpredictable sequence deviations.


Subject(s)
Genome, Fungal , Polymerase Chain Reaction , Saccharomyces cerevisiae/genetics , Base Sequence , Genetic Markers , Molecular Sequence Data , Sequence Homology, Nucleic Acid , Transformation, Genetic
17.
Biochemistry ; 35(3): 883-90, 1996 Jan 23.
Article in English | MEDLINE | ID: mdl-8547269

ABSTRACT

The plasma membrane H(+)-ATPase (Pmal) from Saccharomyces cerevisiae contains 14 histidine residues. The seven most highly conserved of these were selected as targets for oligonucleotide-directed, site-specific mutagenesis. Substitutions at H240, H488, H614, H686, and H914 with a variety of amino acid residues had no effect either on cell viability or on temperature and pH growth sensitivity. In contrast, substitutions at H701, located in the putative fifth membrane-spanning region, with Asp, Gln, or Arg were dominant lethal, indicating that H701 is essential for H(+)-ATPase activity. The mutations H285Q and H285R, but not H285E, located in the hydrophilic beta-stranded domain, were tolerated in normal growth conditions. Growth of H285Q mutants was sensitive to acid pH, indicating impaired in vivo ATPase activity. The H285Q and H285R mutants showed increased in vitro ATPase-specific activity, increased vanadate resistance, increased proton competition of vanadate sensitivity, accelerated ATP hydrolysis rates at a substrate concentration much lower than the Km, and slightly uncoupled proton pumping. The most reasonable hypothesis which would take into account these observations is that H285 would not be involved in the H+ transport process but rather in the E2 to E1 transition step of the ATP hydrolysis catalytic cycle.


Subject(s)
Proton-Translocating ATPases/chemistry , Saccharomyces cerevisiae/enzymology , Cell Membrane/enzymology , Histidine , Kinetics , Mutagenesis, Site-Directed , Proton-Translocating ATPases/physiology , Structure-Activity Relationship
18.
Yeast ; 10(13): 1793-808, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7747518

ABSTRACT

We have constructed and tested a dominant resistance module, for selection of S. cerevisiae transformants, which entirely consists of heterologous DNA. This kanMX module contains the known kanr open reading-frame of the E. coli transposon Tn903 fused to transcriptional and translational control sequences of the TEF gene of the filamentous fungus Ashbya gossypii. This hybrid module permits efficient selection of transformants resistant against geneticin (G418). We also constructed a lacZMT reporter module in which the open reading-frame of the E. coli lacZ gene (lacking the first 9 codons) is fused at its 3' end to the S. cerevisiae ADH1 terminator. KanMX and the lacZMT module, or both modules together, were cloned in the center of a new multiple cloning sequence comprising 18 unique restriction sites flanked by Not I sites. Using the double module for constructions of in-frame substitutions of genes, only one transformation experiment is necessary to test the activity of the promotor and to search for phenotypes due to inactivation of this gene. To allow for repeated use of the G418 selection some kanMX modules are flanked by 470 bp direct repeats, promoting in vivo excision with frequencies of 10(-3)-10(-4). The 1.4 kb kanMX module was also shown to be very useful for PCR based gene disruptions. In an experiment in which a gene disruption was done with DNA molecules carrying PCR-added terminal sequences of only 35 bases homology to each target site, all twelve tested geneticin-resistant colonies carried the correctly integrated kanMX module.


Subject(s)
Genes, Reporter , Genetic Vectors , Genome, Fungal , Mutagenesis, Insertional , Saccharomyces cerevisiae/genetics , Base Sequence , Kanamycin Resistance/genetics , Molecular Sequence Data , Polymerase Chain Reaction , beta-Galactosidase/genetics
19.
J Biol Chem ; 268(26): 19753-9, 1993 Sep 15.
Article in English | MEDLINE | ID: mdl-8396147

ABSTRACT

The PMA1 H(+)-ATPase can be functionally replaced by its isoform PMA2 in the plasma membrane from Saccharomyces cerevisiae (Supply, P., Wach, A., Thinès-Sempoux, D., and Goffeau, A. (1993) J. Biol. Chem. 268, 19744-19752). From strains expressing either only PMA1 or PMA2, plasma membranes were isolated and their ATPase activities compared. Despite their 89% identity, the two enzymes differ as to the following parameters: activation by glucose and by Triton X-100, pH optimum, requirement for divalent cations, and inhibition by vanadate and by erythrosin B. More striking, the glucose-activated PMA2 enzyme displays a three to four times higher apparent affinity for MgATP, and maximal activity is reached with a 10-fold lower free Mg2+ concentration. These results suggest that the difference in PMA1 and PMA2 expression level is correlated with different H(+)-ATPase functions. The analysis of the PMA1 and PMA2 sequence alignment, compared with reported PMA1 mutations, points to a few residue substitutions as putative contributors to the observed kinetic changes.


Subject(s)
Isoenzymes/metabolism , Proton-Translocating ATPases/metabolism , Saccharomyces cerevisiae/enzymology , Amino Acid Sequence , Cell Membrane/enzymology , Detergents/pharmacology , Erythrosine/pharmacology , Isoenzymes/genetics , Kinetics , Magnesium/pharmacology , Molecular Sequence Data , Mutagenesis, Site-Directed , Octoxynol , Polyethylene Glycols/pharmacology , Proton-Translocating ATPases/genetics , Regression Analysis , Saccharomyces cerevisiae/genetics , Sequence Homology, Amino Acid , Sorbitol/pharmacology , Thermodynamics , Vanadates/pharmacology
20.
J Biol Chem ; 268(26): 19744-52, 1993 Sep 15.
Article in English | MEDLINE | ID: mdl-8366114

ABSTRACT

The PMA2 gene is a presumed isogene of the PMA1 gene, encoding the major yeast plasma membrane H(+)-ATPase. When controlled by its own promoter, PMA2 in multiple copies does not complement a deficient PMA1 gene. Under the control of the PMA1 promoter, however, and expressed on a centromeric plasmid in yeast strains specially designed for stable expression, the PMA2 gene replaces the PMA1 gene to some extent, allowing growth on standard medium but not on acidic media. Plasma membranes of cells expressing only the PMA2 enzyme display low ATPase activity correlating with low amounts of PMA2 protein. This low activity is maintained throughout growth and does not increase when overexpression is favored by increased gene dosage. Immunoelectron microscopy reveals a dramatic proliferation of intracellular structures (probably endoplasmic reticulum) in which overexpressed PMA2 protein accumulates. Overexpression of PMA1 ATPase causes a similar phenomenon, but quantitative effects are lower compared to PMA2. These results indicate that the PMA2 gene encodes a functional plasma membrane H(+)-ATPase and suggest a specific control of the intracellular traffic of plasma membrane ATPase.


Subject(s)
Adenosine Triphosphatases/biosynthesis , Adenosine Triphosphatases/genetics , Genes, Fungal , Isoenzymes/biosynthesis , Isoenzymes/genetics , Saccharomyces cerevisiae/enzymology , Acetates/pharmacology , Adenosine Triphosphatases/isolation & purification , Cell Membrane/enzymology , Cell Membrane/ultrastructure , Crosses, Genetic , Gene Deletion , Genetic Complementation Test , Genotype , Isoenzymes/isolation & purification , Microscopy, Immunoelectron , Mutagenesis, Insertional , Plasmids , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/ultrastructure , Vanadates/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL
...