scholarly journals TWO RECESSIVE SUPPRESSORS OF SACCHAROMYCES CEREVISIAE CHO1 THAT ARE UNLINKED BUT FALL IN THE SAME COMPLEMENTATION GROUP

Genetics ◽  
1985 ◽  
Vol 111 (1) ◽  
pp. 1-6
Author(s):  
Katharine D Atkinson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Meiotic Recombination ◽  
Genetic Locus ◽  
Complementation Group ◽  
Complementation Analysis ◽  
Gene Products ◽  
Chromosome X ◽  
Recessive Mutations ◽  
Recessive Mutant ◽  
Phenotypic Reversion

ABSTRACT Phenotypic reversion of ethanolamine-requiring Saccharomyces cerevisiae cho 1 mutants is predominantly due to recessive mutations at genes unlinked to the chromosome V cho 1 locus. The recessive suppressors do not correct the primary cho 1 defect in phosphatidylserine synthesis but circumvent it with a novel endogenous supply of ethanolamine. One suppressor (eam1) was previously mapped to chromosome X, and 135 suppressor isolates were identified as eam1 alleles by complementation analysis. Additional meiotic recombination studies have identified a second genetic locus, eam2, that falls in the eam1 complementation group but maps close to the centromere of chromosome IV. Although the normal EAM1 and EAM2 alleles are fully dominant over recessive mutant alleles, their dominance fails in diploids heterozygous for defects in both genes simultaneously. The unusual complementation pattern could be explained by interaction of the gene products in formation of the same enzyme.

The RAD7 and RAD16 genes, which are essential for pyrimidine dimer removal from the silent mating type loci, are also required for repair of the nontranscribed strand of an active gene in Saccharomyces cerevisiae

1994 ◽  
Vol 14 (9) ◽  
pp. 6135-6142
Author(s):  
R Verhage ◽  
A M Zeeman ◽  
N de Groot ◽  
F Gleig ◽  
D D Bang ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Excision Repair ◽  
Complementation Group ◽  
Pyrimidine Dimer ◽  
Gene Products ◽  
Pyrimidine Dimers ◽  
Nucleotide Excision ◽  
Active Genes ◽  
Silent Mating Type Loci

The rad16 mutant of Saccharomyces cerevisiae was previously shown to be impaired in removal of UV-induced pyrimidine dimers from the silent mating-type loci (D. D. Bang, R. A. Verhage, N. Goosen, J. Brouwer, and P. van de Putte, Nucleic Acids Res. 20:3925-3931, 1992). Here we show that rad7 as well as rad7 rad16 double mutants have the same repair phenotype, indicating that the RAD7 and RAD16 gene products might operate in the same nucleotide excision repair subpathway. Dimer removal from the genome overall is essentially incomplete in these mutants, leaving about 20 to 30% of the DNA unrepaired. Repair analysis of the transcribed RPB2 gene shows that the nontranscribed strand is not repaired at all in rad7 and rad16 mutants, whereas the transcribed strand is repaired in these mutants at a fast rate similar to that in RAD+ cells. When the results obtained with the RPB2 gene can be generalized, the RAD7 and RAD16 proteins not only are essential for repair of silenced regions but also function in repair of nontranscribed strands of active genes in S. cerevisiae. The phenotype of rad7 and rad16 mutants closely resembles that of human xeroderma pigmentosum complementation group C (XP-C) cells, suggesting that RAD7 and RAD16 in S. cerevisiae function in the same pathway as the XPC gene in human cells. RAD4, which on the basis of sequence homology has been proposed to be the yeast XPC counterpart, seems to be involved in repair of both inactive and active yeast DNA, challenging the hypothesis that RAD4 and XPC are functional homologs.

scholarly journals RAD10, an excision repair gene of Saccharomyces cerevisiae, is involved in the RAD1 pathway of mitotic recombination.

1990 ◽  
Vol 10 (6) ◽  
pp. 2485-2491 ◽  
Author(s):  
R H Schiestl ◽  
S Prakash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Meiotic Recombination ◽  
Excision Repair ◽  
Mitotic Recombination ◽  
The Other ◽  
Gene Products ◽  
Repair Gene ◽  
Homologous Chromosomes ◽  
Intrachromosomal Recombination ◽  
Recombination Pathway

The RAD10 gene of Saccharomyces cerevisiae is required for the incision step of excision repair of UV-damaged DNA. We show that the RAD10 gene is also required for mitotic recombination. The rad10 delta mutation lowered the rate of intrachromosomal recombination of a his3 duplication in which one his3 allele has a deletion at the 3' end and the other his3 allele has a deletion at the 5' end (his3 delta 3' his3 delta 5'). The rate of formation of HIS3+ recombinants in the rad10 delta mutant was not affected by the rad1 delta mutation but decreased synergistically in the presence of the rad10 delta mutation in combination with the rad52 delta mutation. These observations indicate that the RAD1 and RAD10 genes function together in a mitotic recombination pathway that is distinct from the RAD52 recombination pathway. The rad10 delta mutation also lowered the efficiency of integration of linear DNA molecules and circular plasmids into homologous genomic sequences. We suggest that the RAD1 and RAD10 gene products act in recombination after the formation of the recombinogenic substrate. The rad1 delta and rad10 delta mutations did not affect meiotic intrachromosomal recombination of the his3 delta 3' his3 delta 5' duplication or mitotic and meiotic recombination of ade2 heteroalleles located on homologous chromosomes.

scholarly journals SACCHAROMYCES CEREVISIAE RECESSIVE SUPPRESSOR THAT CIRCUMVENTS PHOSPHATIDYLSERINE DEFICIENCY

Genetics ◽  
1984 ◽  
Vol 108 (3) ◽  
pp. 533-543 ◽  
Author(s):  
Katharine D Atkinson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lipid Synthesis ◽  
Phospholipid Synthesis ◽  
Chromosome X ◽  
Tetrad Analysis ◽  
Phenotypic Reversion

ABSTRACT Phenotypic reversion of six independent Saccharomyces cerevisiae cho1 mutants was shown to be due predominantly to mutation of an unlinked gene, eam1. The eam1 gene was located very close to ino1 on chromosome X by meiotic tetrad analysis. Recessive eam1 mutations did not correct the primary cho1 defect in phosphatidylserine synthesis but made endogenous ethanolamine available for sustained nitrogenous phospholipid synthesis. A novel biochemical contribution to nitrogenous lipid synthesis is indicated by the eam1 mutants.

RAD10, an excision repair gene of Saccharomyces cerevisiae, is involved in the RAD1 pathway of mitotic recombination

1990 ◽  
Vol 10 (6) ◽  
pp. 2485-2491
Author(s):  
R H Schiestl ◽  
S Prakash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Meiotic Recombination ◽  
Excision Repair ◽  
Mitotic Recombination ◽  
The Other ◽  
Gene Products ◽  
Repair Gene ◽  
Homologous Chromosomes ◽  
Intrachromosomal Recombination ◽  
Recombination Pathway

The RAD10 gene of Saccharomyces cerevisiae is required for the incision step of excision repair of UV-damaged DNA. We show that the RAD10 gene is also required for mitotic recombination. The rad10 delta mutation lowered the rate of intrachromosomal recombination of a his3 duplication in which one his3 allele has a deletion at the 3' end and the other his3 allele has a deletion at the 5' end (his3 delta 3' his3 delta 5'). The rate of formation of HIS3+ recombinants in the rad10 delta mutant was not affected by the rad1 delta mutation but decreased synergistically in the presence of the rad10 delta mutation in combination with the rad52 delta mutation. These observations indicate that the RAD1 and RAD10 genes function together in a mitotic recombination pathway that is distinct from the RAD52 recombination pathway. The rad10 delta mutation also lowered the efficiency of integration of linear DNA molecules and circular plasmids into homologous genomic sequences. We suggest that the RAD1 and RAD10 gene products act in recombination after the formation of the recombinogenic substrate. The rad1 delta and rad10 delta mutations did not affect meiotic intrachromosomal recombination of the his3 delta 3' his3 delta 5' duplication or mitotic and meiotic recombination of ade2 heteroalleles located on homologous chromosomes.

Bipartite structure of an early meiotic upstream activation sequence from Saccharomyces cerevisiae

1993 ◽  
Vol 13 (4) ◽  
pp. 2172-2181
Author(s):  
K S Bowdish ◽  
A P Mitchell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Product ◽  
Mutational Analysis ◽  
Regulatory Region ◽  
Gene Products ◽  
Upstream Activation Sequence ◽  
Recessive Mutations ◽  
Sequence Elements ◽  
Selection For ◽  
Activation Sequence

Diploid a/alpha Saccharomyces cerevisiae cells cease mitotic growth and enter meiosis in response to starvation. Expression of meiotic genes depends on the IME1 gene product, which accumulates only in meiotic cells. We report here an analysis of the regulatory region of IME2, an IME1-dependent meiotic gene. Deletion and substitution studies identified a 48-bp IME1-dependent upstream activation sequence (UAS). Activity of the UAS also requires the RIM11, RIM15, and RIM16 gene products, which are required for expression of the chromosomal IME2 promoter and for meiosis. Through a selection for suppressors that permit UAS activity in an ime1 deletion mutant, we identified recessive mutations in three genes, SIN3 (also called RPD1, UME4, and SDI1), RPD3, and UME6 (also called CAR80), that were previously known as negative regulators of other early meiotic genes. Mutational analysis of the IME2 UAS reveals two critical sequence elements: a G+C-rich sequence (called URS1), previously identified at many meiotic genes, and a newly described element, the T4C site, that we found at a subset of meiotic genes. In agreement with prior studies, URS1 mutations lead to elevated IME2 UAS activity in the absence of IME1. However, the URS1 mutations prevent any further stimulation of UAS activity by IME1. Repression through URS1 has been shown to require the UME6 gene product. We find that activation of the IME2 UAS by IME1 also requires the UME6 gene product. Thus, UME6 and the URS1 site both have dual negative and positive roles at the IME2 UAS. We propose that IME1 modifies UME6 to convert it from a negulator to a positive Regulor.

scholarly journals The RAD7 and RAD16 genes, which are essential for pyrimidine dimer removal from the silent mating type loci, are also required for repair of the nontranscribed strand of an active gene in Saccharomyces cerevisiae.

1994 ◽  
Vol 14 (9) ◽  
pp. 6135-6142 ◽  
Author(s):  
R Verhage ◽  
A M Zeeman ◽  
N de Groot ◽  
F Gleig ◽  
D D Bang ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Excision Repair ◽  
Complementation Group ◽  
Pyrimidine Dimer ◽  
Gene Products ◽  
Pyrimidine Dimers ◽  
Nucleotide Excision ◽  
Active Genes ◽  
Silent Mating Type Loci

The rad16 mutant of Saccharomyces cerevisiae was previously shown to be impaired in removal of UV-induced pyrimidine dimers from the silent mating-type loci (D. D. Bang, R. A. Verhage, N. Goosen, J. Brouwer, and P. van de Putte, Nucleic Acids Res. 20:3925-3931, 1992). Here we show that rad7 as well as rad7 rad16 double mutants have the same repair phenotype, indicating that the RAD7 and RAD16 gene products might operate in the same nucleotide excision repair subpathway. Dimer removal from the genome overall is essentially incomplete in these mutants, leaving about 20 to 30% of the DNA unrepaired. Repair analysis of the transcribed RPB2 gene shows that the nontranscribed strand is not repaired at all in rad7 and rad16 mutants, whereas the transcribed strand is repaired in these mutants at a fast rate similar to that in RAD+ cells. When the results obtained with the RPB2 gene can be generalized, the RAD7 and RAD16 proteins not only are essential for repair of silenced regions but also function in repair of nontranscribed strands of active genes in S. cerevisiae. The phenotype of rad7 and rad16 mutants closely resembles that of human xeroderma pigmentosum complementation group C (XP-C) cells, suggesting that RAD7 and RAD16 in S. cerevisiae function in the same pathway as the XPC gene in human cells. RAD4, which on the basis of sequence homology has been proposed to be the yeast XPC counterpart, seems to be involved in repair of both inactive and active yeast DNA, challenging the hypothesis that RAD4 and XPC are functional homologs.

scholarly journals Selection for early meiotic mutants in yeast.

Genetics ◽  
1992 ◽  
Vol 131 (1) ◽  
pp. 65-72 ◽  
Author(s):  
A P Mitchell ◽  
K S Bowdish
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Meiotic Recombination ◽  
Alpha Cells ◽  
Cell Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Meiotic Mutants ◽  
Recessive Mutations ◽  
Lethal Damage ◽  
Selection For ◽  
Diploid Cells

Abstract In the yeast Saccharomyces cerevisiae, only a/alpha cells can enter meiosis; a and alpha cells cannot. Because a/alpha cells are typically diploid and a and alpha cells are typically haploid, this cell type restriction ensures that only diploid cells enter meiosis. Entry into meiosis is accompanied by an increase in expression of the IME1 gene; the IME1 product (IME1) then activates IME2 and other meiotic genes. We have found that IME1 expression is toxic to starved haploid cells, presumably because IME1 directs them into meiosis. IME1 toxicity is greater in rad52 mutants, in which meiotic recombination causes lethal damage. Suppressors of IME1 toxicity include recessive mutations in two genes, RIM11 and RIM16 (Regulator of Inducer of Meiosis), that are required for IME1 to activate IME2 expression. RIM11 maps near CIN4 on chromosome XIII.

scholarly journals Bipartite structure of an early meiotic upstream activation sequence from Saccharomyces cerevisiae.

1993 ◽  
Vol 13 (4) ◽  
pp. 2172-2181 ◽  
Author(s):  
K S Bowdish ◽  
A P Mitchell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Product ◽  
Mutational Analysis ◽  
Regulatory Region ◽  
Gene Products ◽  
Upstream Activation Sequence ◽  
Recessive Mutations ◽  
Sequence Elements ◽  
Selection For ◽  
Activation Sequence

Diploid a/alpha Saccharomyces cerevisiae cells cease mitotic growth and enter meiosis in response to starvation. Expression of meiotic genes depends on the IME1 gene product, which accumulates only in meiotic cells. We report here an analysis of the regulatory region of IME2, an IME1-dependent meiotic gene. Deletion and substitution studies identified a 48-bp IME1-dependent upstream activation sequence (UAS). Activity of the UAS also requires the RIM11, RIM15, and RIM16 gene products, which are required for expression of the chromosomal IME2 promoter and for meiosis. Through a selection for suppressors that permit UAS activity in an ime1 deletion mutant, we identified recessive mutations in three genes, SIN3 (also called RPD1, UME4, and SDI1), RPD3, and UME6 (also called CAR80), that were previously known as negative regulators of other early meiotic genes. Mutational analysis of the IME2 UAS reveals two critical sequence elements: a G+C-rich sequence (called URS1), previously identified at many meiotic genes, and a newly described element, the T4C site, that we found at a subset of meiotic genes. In agreement with prior studies, URS1 mutations lead to elevated IME2 UAS activity in the absence of IME1. However, the URS1 mutations prevent any further stimulation of UAS activity by IME1. Repression through URS1 has been shown to require the UME6 gene product. We find that activation of the IME2 UAS by IME1 also requires the UME6 gene product. Thus, UME6 and the URS1 site both have dual negative and positive roles at the IME2 UAS. We propose that IME1 modifies UME6 to convert it from a negulator to a positive Regulor.

scholarly journals Suppressor Analysis of Mutations in the 5′-Untranslated Region of COB mRNA Identifies Components of General Pathways for Mitochondrial mRNA Processing and Decay in Saccharomyces cerevisiae

Genetics ◽  
1999 ◽  
Vol 151 (4) ◽  
pp. 1315-1325
Author(s):  
Wei Chen ◽  
Maria A Islas-Osuna ◽  
Carol L Dieckmann
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Untranslated Region ◽  
Mitochondrial Rna ◽  
Rna Turnover ◽  
Single Nucleotide ◽  
Mrna Stabilization ◽  
Recessive Mutations ◽  
A Subunit ◽  
Suppressor Analysis ◽  
Dominant Suppressor

Abstract The cytochrome b gene in Saccharomyces cerevisiae, COB, is encoded by the mitochondrial genome. Nuclear-encoded Cbp1 protein is required specifically for COB mRNA stabilization. Cbp1 interacts with a CCG element in a 64-nucleotide sequence in the 5′-untranslated region of COB mRNA. Mutation of any nucleotide in the CCG causes the same phenotype as cbp1 mutations, i.e., destabilization of both COB precursor and mature message. In this study, eleven nuclear suppressors of single-nucleotide mutations in CCG were isolated and characterized. One dominant suppressor is in CBP1, while the other 10 semidominant suppressors define five distinct linkage groups. One group of four mutations is in PET127, which is required for 5′ end processing of several mitochondrial mRNAs. Another mutation is linked to DSS1, which is a subunit of mitochondrial 3′ → 5′ exoribonuclease. A mutation linked to the SOC1 gene, previously defined by recessive mutations that suppress cbp1 ts alleles and stabilize many mitochondrial mRNAs, was also isolated. We hypothesize that the products of the two uncharacterized genes also affect mitochondrial RNA turnover.

scholarly journals Poorly Repaired Mismatches in Heteroduplex DNA are Hyper-Recombinagenic in Saccharomyces cerevisiae

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 407-416 ◽  
Author(s):  
P Manivasakam ◽  
Susan M Rosenberg ◽  
P J Hastings
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mismatch Repair ◽  
Genetic Markers ◽  
Meiotic Recombination ◽  
Repair System ◽  
Normal Allele ◽  
Heteroduplex Dna ◽  
Mismatch Repair System ◽  
Postmeiotic Segregation ◽  
System Operating

Abstract In yeast meiotic recombination, alleles used as genetic markers fall into two classes as regards their fate when incorporated into heteroduplex DNA. Normal alleles are those that form heteroduplexes that are nearly always recognized and corrected by the mismatch repair system operating in meiosis. High PMS (postmeiotic segregation) alleles form heteroduplexes that are inefficiently mismatch repaired. We report that placing any of several high PMS alleles very close to normal alleles causes hyperrecombination between these markers. We propose that this hyperrecombination is caused by the high PMS allele blocking a mismatch repair tract initiated from the normal allele, thus preventing corepair of the two alleles, which would prevent formation of recombinants. The results of three point crosses involving two PMS alleles and a normal allele suggest that high PMS alleles placed between two alleles that are normally corepaired block that corepair.

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