摘要:

AbstractMercaptoethanol and dithiothreitol (DTT) inhibited the acidification of external medium by bySaccharomyces Carlsbergensiscells and protoplasts during glucose oxidation. The inhibition was also observed when cells were incubated with mercaptoethanol or when mercaptoethanol and DTT were used to prepare protolasts. Experiments withS. carlsbergensisplasma membrene vesicles and vacuoles showed these thiol reagents to inhibitATP‐dipendent generation of ΔpH andEmacross plasma membrane vesicles and vacuoles but to activate their H+‐ATPases. Mercaptoethanol and DTT are suggested to de‐energize plasmalemma as well as tonoplast by increasing their H+‐permeability and to disturb the cell ion hom

ISSN:0749-503X    

DOI:10.1002/yea.320080803

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractChromosomal DNAs of many monosporic strains of the biological speciesSaccharomyces cerevisiae, S. paradoxusandS. bayanuswere analysed using contour‐clamped homogeneous electric field electrophgoresis. SSouthern blot hybridization with eight clonedS. cerevisiaegenes (ADC1, CUP1, GAL4, LEU2, rDNA, SUC2, TRP1andURA3) assigned to different chromosomes was used to study homology and chromosomal location of the genes three sibiling species. A comparative study ofTy1, Ty2and telomere‐associated Y' sequences having multiple chromosomal location was also done.Chromosome length polymorphism was found in cultured strains ofS. cerevisiae. WildS. cerevisiaeandS. paradoxusstrains yielded chromosome banding patterns very similar to each other, The karyotype pattern ofS. bayanuswas readily distinguishable from that ofS. cerevisiaeandS. paradoxus. Southern blot analysis revealed a low degree of homology between theS. cerevisiaegenes studied and the correspondingS. paradoxusandS. bayanusgenes. The number of chromosomes appears to be 16 in all three spec

ISSN:0749-503X    

DOI:10.1002/yea.320080804

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractWe describe the isolation of mutants of the yeastPichia pastoristhat are deficient in peroxisome assembly (pas). These mutants ofP. pastoriscan be identified solely by their inability to grow on methanol and oleic acid, the utilization of which requires peroxisomal enzymes, and are defined by the absence of normal peroxisomes as judged by electron microscopy and biochemical fractionation experiments. These mutants are the result of genetic defects at single loci and represent at least eight different complementation groups. The isolation ofpasmutants ofP. pastorisby a simple screen for mutants unable to use methanol and oleic acid represents a significantly more efficient method for identification ofpasmutants than is possible in other organisms. To exploit this advantage fully we also developed new reagents for the genetic and molecular manipulation ofP. pastoris. These include a set of auxotropic strains with an essentialiy wild type genetic background, plasmids that act asEscherichia coli–P. pastorisshuttle vectors, and genomic DNA libraries for isolation ofP. pastorisgenes by functional complementation of mutants or by nucleic acid hybridization. The availability of numerouspasmutants and the reagents necessary for their molecular analysis should lead to the isolation and characterization of genes involved in peroxisome assembl

ISSN:0749-503X    

DOI:10.1002/yea.320080805

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractA genetal method is described for screeningSaccharomyces cerevisiaecolonies for the intracellular expression of native proteins. Colonies are replicated onto nitrocellulose membranes and yeast walls are removed enzymatically. The resulting spheroplasts are rapidly lysed by placing chromatography paper soaked in hypotonic buffer on the membranes. Intracellular proteins released by spheroplast lysis are boundin situto the nitrocllulose under non‐denaturing conditions and potentially can be examined using enzymatic or immunologeic methods. For example, in the present study colonies were screened for the presence of elongation factor 2 (EF‐2) that can be [32P]ADP‐ribosylated by diphtheria toxin and [32P]NAD+. Recognition by the toxin requires the presence in EF‐2 of the unique posttranslationally modifed histidine derivative, dipthamide. The procedure described here reliably discriminates between wild‐type yeast colonies and mutant colonies that do not synthesize diphthamide. In addition to faciliating the study of dipthamide biosynthesis in yeast, the more general application of this procedure of this procedure will enable the screening of colonies with assays that require native

ISSN:0749-503X    

DOI:10.1002/yea.320080806

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractYeast flocculation involves the binding of surface lectins on flocculent yeasts, to carbohydrate receptors present as constituents of yeast cell walls. Receptors were investigated by coflocculation of flocculent strains ofSaccharomyces cerevisiae, both Flo 1 and NewFlo phenotypes, to knownmnnmutants which vary in the wall mannan structure. Strong coflocculation was found withmnn1,mnn4,mnn9and control strains, while very little coflocculation was found withmnn2andmnn5strains. In constrast, aggregation of these muatants by concanavalin A, a lectin with similar sugar inhibition to NewFlo phenotype flocculation, showed strong aggregation ofmnn1,mnn4, andmnn5strains and poor aggregation ofmnn2andmnn9strains.Themmnmutant data suggested that flocculation receptorss were the outer‐chain mannan side‐branches, two or three mannose residues in length, confirming an earlier theory based on sugar inhibition data. The similarities and differences between flocculation and concanavalin A aggregation are discus

ISSN:0749-503X    

DOI:10.1002/yea.320080807

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractWe have developed a system for testing mutations by plasmid exchange in the fissionSchizosaccharomyces pombe. This system has been used to test the requirement for different regions of the small nuclear RNA U4 inS. pombe. Surprisingly, five of seven deletion and substitution mutations tested in different regions of U4 prevent the accumulation of the mutant RNA. Substitution of the U4 sequence in stem 1 of the U4/U6 interaction doamain allows accumuation of the mutant U4, but does not supports viability. Two sequences with homology to the Sm binding site are found in the 3′ region ofS. pombeU4; substitution of the 3′ sequence of the two does not interfere with accumulation or function of U4, indicating that the 5′ sequence is the functional Sm‐bindi

ISSN:0749-503X    

DOI:10.1002/yea.320080808

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractSaccharomycesstrains capable of fermenting maltose contain any one of five telomere‐associatedMALloci. EachMALlocus is a complex of three genes encoding the three functions required to ferment maltos: maltose permease (GENE 1), maltase (GENE 2) and theMAL trans‐activator (GENE 3). All five loci have been cloned and all are highly sequence homologous over least a 9‐0 kbp region containing these GENEs (Charronet al.,Genetics122, 307–331, 1989). Our initial studies of strians carrying theMAL3locus indicated the presence of linked, repeatedMLA‐homologous sequences (Michels and Needleman,Mol. Gen. Genet.191, 225–230, 1983). Here we report our analysis of the centromere‐proximalMAL3‐linked sequence and show that the completeMAL3locus spans approximately 40 kbp and consists of tandemly arrayed, partial repeats of the three GENE sequences described above. In addition, the structure of theMAL3locus is compared to that of three partially functional alleles ofMAL3. These alleles were shown to contain onlyMAL31andMAL32and their structure suggests that they resulted fromMAL3deletions removing the sequences centromere‐proximal ofMAL31. The amplification and rerrangement of the telomer‐linkedMAL3sequences are discussed in the context of studies on other telemere‐associated sequences from ye

ISSN:0749-503X    

DOI:10.1002/yea.320080809

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe recently dsecribed dominant yeast markerTn5bleconfers phleomycin resistance on the yeastSaccharomyces cerevisiae(Gatignol, Baron and Tiraby, 1987.Mol. Gen. Genet.207, 342–348). Incubation in non‐selective medium prior to selection is critical, however, for getting phleomycin‐resistant transformants. A 6‐h incubation period was found to give optimal transformation frequencies, up to 105transformants/μg plasmid, comparable to selection for uracil prototroph

ISSN:0749-503X    

DOI:10.1002/yea.320080810

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

ISSN:0749-503X    

DOI:10.1002/yea.320080811

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractFKB2encodes a homolog of human FKBP‐13, a membrane‐associated binding protein for the immunosuppressants FK506 and rapamycin.FKB2is located on the right arm of chromosome IV and contains an open reading frame of 135 amino acids, of which the first 17 residues comprise a putative hydrophobic leader peptide. Yeast FKBP‐13 is homologous to human FKBP‐13 (52% amino acid identity) and to FKBP‐12, the major cytosolic receptor for FK506. In the alignment of FKBP‐13 and FKBP‐12 sequences, there are 28 invariant residues. Among these conserved residues are those that comprise the drug binding and peptidyl‐prolylcis‐transisomerase active site of FKBP‐12. The phylogenetic conservation of the FKBP family suggests that the proteins are involved in a basi

ISSN:0749-503X    

DOI:10.1002/yea.320080812

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY