ISSN:0749-503X    

DOI:10.1002/yea.320010102

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

ISSN:0749-503X    

DOI:10.1002/yea.320010103

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractTheppd1mutant of yeast,Saccharomyces cerevisiae, was isolated as a suppressor of thecyr2mutation which caused alteration of the catalytic subunit of cAMP‐dependent protein kinase. Three peaks of phosphoprotein phosphatase activity (peak I, II and III) were identified by DEAE‐Sephacel chromatography of crude extracts of the wild‐type strain. Theppd1mutant was deficient in peak III phosphoprotein phosphatase activity. The peak III enzyme efficiently utilized the phosphorylated forms of NAD‐dependent glutamate dehydrogenase and trehalase as substrate. Theppd1mutation did not suppress thecyr1,CYR3orras1 ras2mutations. Theppd1locus was located on chromosome II and had identical characteristcs withglc1. Theppd1mutation suppressed the G1 arrest caused by nutritional limitation, but maintained sensitivity to mating pheromone. In diploids homozygous for theppd1mutation, no premeiotic DNA replication and commitment to intragenic recombination occurred and no spores were formed, suggesting that the accumulation of phosphorylated proteins in the absence of one of the phosphoprotein phosphatases is required for mitosis but not for the initiation of

ISSN:0749-503X    

DOI:10.1002/yea.320010104

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractIn an apomitic strain ofSaccharomyces cerevisiae(ATCC 4117‐H2) which undergoes a single nuclear division during sporulation and consequently forms asci containing two uninucleate diploid spores, a study was undertaken to investigate the effects of cultivation in three presporulation media (YPA; YNB; SMM) on nuclear division and ascoporogenesis in sporulation medium. Comparison of effects of presporulation culture in these media on the number of spores formed per ascus showed that a marked induction (30 ± 4·3 per cent) of three‐ and four‐spored asci could occur in sporulation medium following cultivation in a defined YNB medium supplemented with a 1 per cent solution of vitamins and containing decreased ammonium sulphate and increased glucose levels. Experiments in which the concentrations of glucose and of ammonium sulphate were varied simultaneously indicated that the initial presporulation carbon to nitrogen source ratio is an important factor in determining tetrad formation in sporulation medium. Nuclear staining demonstrated two classes of asci: binucleate (one‐ and two‐spored) and tetranucleate (three‐ and four‐spored). Genetic evidence and data concerning effects of inclusion in sporulation medium of a meiotic inhibitor (glucose) indicated spores in tetrads were haploid rather than diploid. This ability to condition a significant number of cells for meiotic rather than apomictic differentiation made possible investigation of effects of mitochondrial inhibitors on both developmental processes simultaneously. It was found possible to selectively inhibit meiotic development by inclusion in sporulation medium of appropriate concentrations of specific inhibitors. Moreover, the data suggest meiotic sporulation is more strictly dependent than apomictic sporulation on mitocho

ISSN:0749-503X    

DOI:10.1002/yea.320010105

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractPlasmid pPW229, containing the 2·25 kilobase transcribed sequence for the 70 000 Dalton heat shock protein ofDrosophila,1was integrated into plasmid CV13 and used to transformSaccharomyces cerevisiae. Upon a heat shock, at 41°C for 20 min, a new 70 000 Dalton protein appeared in the transformants. This protein was not detected in transformants grown at 23°C, nor in transfromants carrying the hybrid plasmid from which the structural gene for the 70 000 Dalton protein had been deleted. RNA was isolated from transromants grown at 23°C and from transformants heat shocked at 41°C. RNA complementary to theDrosophilaheat shock gene was present in the transformants, grown either at 23°C or heat shocked. No complementary RNA was detected in yeast cells transformed with the hybrid plasmid from which the structural gene had been deleted. TheDrosophilaheat shock gene in yeast appears to be transcribed constitutively but translated only under heat shock condi

ISSN:0749-503X    

DOI:10.1002/yea.320010106

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractL–A–E double‐stranded RNA (dsRNA), when introduced into cells carrying L–A–H and M2dsRNAs, does not eliminate the L–A–H dsRNA, but (i) L–A–E does lower the copy number of L–A–H dramatically and (ii) L–A–E eliminates M2dsRNA from the cell. That these two effects of L–A–E are related is shown by the fact that mutants of a strain carrying L–A–H and M2selected for their resistance to exclusion of M2by L–A–E [effect (ii)] have an altered L–A–H whose copy number is not lowered by L–A–E [effect (i)]. Although the L–A in K1strains (L–A–HN in all cases examined) differs significantly both genetically and physically from the L–A in the K2strain studied (L–A–H), the L–A–HN from the K1strains can maintain M

ISSN:0749-503X    

DOI:10.1002/yea.320010107

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

摘要:

AbstractWe present the nucleotide sequence of a 1599‐base pair (bp) DNA fragment containing the entireGAL7gene that encodes galactose‐1‐phosphate uridyltransferase ofSaccharomyces cerevisiae. The deduced peptide was composed of 364 amino acid residues. The expected molecular weight was 42 005 daltons, which agreed with the observed value for the purified enzyme.1The 3′‐end of theGAL7transcript mapped at a position 82 bp downstream from the UAA termination codon by the S1 nuclease protection experiment. We constructed aGAL7′‐lac′Zfusion on various types of yeast plasmid vectors. The fused gene on any type of vector was induced by galactose and repressed by glucose as for theGAL7gene on the chromosome. The response ofGAL7′‐lac′Zfusion togal4Δandgal80Δregulatory mutations was also similar to the response of the chromosomalGAL7gene. By using various deletions in the 5′‐flanking region of the gene fusion, we delimited the sequence essential for galactose controlled expression with a 180 bp‐fragment of DNA lying 92 bp upstream of the

ISSN:0749-503X    

DOI:10.1002/yea.320010108

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

ISSN:0749-503X    

DOI:10.1002/yea.320010109

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

ISSN:0749-503X    

DOI:10.1002/yea.320010110

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY

ISSN:0749-503X    

DOI:10.1002/yea.320010101

出版商:John Wiley&Sons, Ltd.    

年代:1985

数据来源: WILEY