Recombination and mating-type switching in a ligase-defective mutant of Schizosaccharomyces pombe

1990 ◽  
Vol 220 (2) ◽  
pp. 307-313 ◽  
Author(s):  
M. Sipiczki ◽  
A.-M. Grossenbacher-Grunder ◽  
Zs. Bódi
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Mating Type ◽  
Defective Mutant ◽  
Mating Type Switching

Sap1, a protein that binds to sequences required for mating-type switching, is essential for viability in Schizosaccharomyces pombe

1994 ◽  
Vol 14 (3) ◽  
pp. 2058-2065
Author(s):  
B Arcangioli ◽  
T D Copeland ◽  
A J Klar
Keyword(s):  
Dna Binding ◽  
Schizosaccharomyces Pombe ◽  
Mating Type ◽  
Biochemical Characterization ◽  
Strand Break ◽  
Double Strand Break ◽  
Type Locus ◽  
Protein Motifs ◽  
Mating Type Switching

The pattern of mating-type switching in cell pedigrees of the fission yeast Schizosaccharomyces pombe is dictated by the inheritance of specific DNA chains at the mating-type locus (mat1). The recombination event essential for switching is initiated by a site-specific double-strand break at mat1. The switch-activating protein, Sap1, binds in vitro to a mat1 cis-acting site that was shown earlier to be essential for efficient mating-type switching. We isolated the sap1 gene by using oligonucleotides corresponding to the amino acid sequence of purified Sap1 protein. The sequence of that gene predicted a 30-kDa protein with no significant homology to other canonical DNA-binding protein motifs. To facilitate its biochemical characterization, Sap1 was expressed in Escherichia coli. The protein expressed in bacteria displayed the same DNA-binding specificities as the protein purified from S. pombe. Interestingly, analysis of a sap1 null mutation showed that the gene is essential for growth even in a strain in which mating-type switching is prohibited because of a defect in generation of the double-strand break. Thus, the sap1 gene product implicated in mating-type switching is shown to be essential for cell viability.

scholarly journals Sap1, a protein that binds to sequences required for mating-type switching, is essential for viability in Schizosaccharomyces pombe.

1994 ◽  
Vol 14 (3) ◽  
pp. 2058-2065 ◽  
Author(s):  
B Arcangioli ◽  
T D Copeland ◽  
A J Klar
Keyword(s):  
Dna Binding ◽  
Schizosaccharomyces Pombe ◽  
Mating Type ◽  
Biochemical Characterization ◽  
Strand Break ◽  
Double Strand Break ◽  
Type Locus ◽  
Protein Motifs ◽  
Mating Type Switching

The pattern of mating-type switching in cell pedigrees of the fission yeast Schizosaccharomyces pombe is dictated by the inheritance of specific DNA chains at the mating-type locus (mat1). The recombination event essential for switching is initiated by a site-specific double-strand break at mat1. The switch-activating protein, Sap1, binds in vitro to a mat1 cis-acting site that was shown earlier to be essential for efficient mating-type switching. We isolated the sap1 gene by using oligonucleotides corresponding to the amino acid sequence of purified Sap1 protein. The sequence of that gene predicted a 30-kDa protein with no significant homology to other canonical DNA-binding protein motifs. To facilitate its biochemical characterization, Sap1 was expressed in Escherichia coli. The protein expressed in bacteria displayed the same DNA-binding specificities as the protein purified from S. pombe. Interestingly, analysis of a sap1 null mutation showed that the gene is essential for growth even in a strain in which mating-type switching is prohibited because of a defect in generation of the double-strand break. Thus, the sap1 gene product implicated in mating-type switching is shown to be essential for cell viability.

The rad16 gene of Schizosaccharomyces pombe: a homolog of the RAD1 gene of Saccharomyces cerevisiae

1994 ◽  
Vol 14 (3) ◽  
pp. 2029-2040
Author(s):  
A M Carr ◽  
H Schmidt ◽  
S Kirchhoff ◽  
W J Muriel ◽  
K S Sheldrick ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Schizosaccharomyces Pombe ◽  
Mating Type ◽  
Excision Repair ◽  
Radiation Sensitivity ◽  
Reading Frame ◽  
Uv Sensitivity ◽  
Protein Protein Interaction ◽  
Mating Type Switching

The rad10, rad16, rad20, and swi9 mutants of the fission yeast Schizosaccharomyces pombe, isolated by their radiation sensitivity or abnormal mating-type switching, have been shown previously to be allelic. We have cloned DNA correcting the UV sensitivity or mating-type switching phenotype of these mutants and shown that the correcting DNA is encompassed in a single open reading frame. The gene, which we will refer to as rad16, is approximately 3 kb in length, contains seven introns, and encodes a protein of 892 amino acids. It is not essential for viability of S. pombe. The predicted protein is the homolog of the Saccharomyces cerevisiae RAD1 protein, which is involved in an early step in excision-repair of UV damage from DNA. The approximately 30% sequence identity between the predicted proteins from the two yeasts is distributed throughout the protein. Two-hybrid experiments indicate a strong protein-protein interaction between the products of the rad16 and swi10 genes of S. pombe, which mirrors that reported for RAD1 and RAD10 in S. cerevisiae. We have identified the mutations in the four alleles of rad16. They mapped to the N-terminal (rad10), central (rad20), and C-terminal (rad16 and swi9) regions. The rad10 and rad20 mutations are in the splice donor sequences of introns 2 and 4, respectively. The plasmid correcting the UV sensitivity of the rad20 mutation was missing the sequence corresponding to the 335 N-terminal amino acids of the predicted protein. Neither smaller nor larger truncations were, however, able to correct its UV sensitivity.

scholarly journals Euchromatin factors HULC and Set1C affect heterochromatin organization for mating-type switching in fission yeast Schizosaccharomyces pombe

2021 ◽  
Author(s):  
Alfredo Esquivel Chavez ◽  
Takahisa Maki ◽  
Hideo Tsubouchi ◽  
Testuya Handa ◽  
Hiroshi Kimura ◽  
...  
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Mating Type ◽  
M Cells ◽  
Cell Type ◽  
M Cell ◽  
Ubiquitin Ligase Complex ◽  
Mating Type Switching ◽  
Histone H3k4 ◽  
Strand Invasion

Mating-type switching (MTS) in fission yeast Schizosaccharomyces pombe is a highly regulated gene conversion event. In the process, heterochromatic donors of genetic information are selected based on the P or M cell type and on the use of two recombination enhancers, SRE2 promoting use of mat2-P and SRE3 promoting use of mat3-M. Recently, we found that the histone H3K4 methyltransferase complex Set1C participates in donor selection, raising the question of how a complex best known for its effects in euchromatin controls recombination in heterochromatin. Here, we report that the histone H2BK119 ubiquitin ligase complex HULC functions with Set1C in MTS, as mutants in the shf1, brl1, brl2 and rad6 genes showed defects similar to Set1C mutants and belonged to the same epistasis group as set1Δ. Moreover, using H3K4R and H2BK119R histone mutants and a Set1-Y897A catalytic mutant indicated that ubiquitylation of histone H2BK119 by HULC and methylation of histone H3K4 by Set1C are functionally coupled in MTS. Cell-type biases in mutants further showed that the regulation might be by inhibiting use of the SRE3 enhancer in M cells, in favor of SRE2. Consistently, imbalanced switching in the mutants was traced to compromised association of the directionality factor Swi6 with the recombination enhancers in M cells. Based on their known effects at other chromosomal locations, we speculate that HULC and Set1C might control nucleosome mobility and strand invasion near the SRE elements. In addition, we uncovered distinct effects of HULC and Set1C on histone H3K9 methylation and gene silencing, consistent with additional functions in the heterochromatic domain.

scholarly journals The rad16 gene of Schizosaccharomyces pombe: a homolog of the RAD1 gene of Saccharomyces cerevisiae.

1994 ◽  
Vol 14 (3) ◽  
pp. 2029-2040 ◽  
Author(s):  
A M Carr ◽  
H Schmidt ◽  
S Kirchhoff ◽  
W J Muriel ◽  
K S Sheldrick ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Schizosaccharomyces Pombe ◽  
Mating Type ◽  
Excision Repair ◽  
Radiation Sensitivity ◽  
Reading Frame ◽  
Uv Sensitivity ◽  
Protein Protein Interaction ◽  
Mating Type Switching

The rad10, rad16, rad20, and swi9 mutants of the fission yeast Schizosaccharomyces pombe, isolated by their radiation sensitivity or abnormal mating-type switching, have been shown previously to be allelic. We have cloned DNA correcting the UV sensitivity or mating-type switching phenotype of these mutants and shown that the correcting DNA is encompassed in a single open reading frame. The gene, which we will refer to as rad16, is approximately 3 kb in length, contains seven introns, and encodes a protein of 892 amino acids. It is not essential for viability of S. pombe. The predicted protein is the homolog of the Saccharomyces cerevisiae RAD1 protein, which is involved in an early step in excision-repair of UV damage from DNA. The approximately 30% sequence identity between the predicted proteins from the two yeasts is distributed throughout the protein. Two-hybrid experiments indicate a strong protein-protein interaction between the products of the rad16 and swi10 genes of S. pombe, which mirrors that reported for RAD1 and RAD10 in S. cerevisiae. We have identified the mutations in the four alleles of rad16. They mapped to the N-terminal (rad10), central (rad20), and C-terminal (rad16 and swi9) regions. The rad10 and rad20 mutations are in the splice donor sequences of introns 2 and 4, respectively. The plasmid correcting the UV sensitivity of the rad20 mutation was missing the sequence corresponding to the 335 N-terminal amino acids of the predicted protein. Neither smaller nor larger truncations were, however, able to correct its UV sensitivity.

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