scholarly journals Identification of a protein that binds to the Ho endonuclease recognition sequence at the yeast mating type locus.

1997 ◽  
Vol 17 (2) ◽  
pp. 770-777 ◽  
Author(s):  
R Wang ◽  
Y Jin ◽  
D Norris
Keyword(s):  
Mating Type ◽  
Recognition Sequence ◽  
Mobility Shift ◽  
Vitro Assay ◽  
Type Locus ◽  
Mating Type Locus ◽  
Yeast Mating ◽  
Mating Type Switching

Mating type switching in Saccharomyces cerevisiae initiates when Ho endonuclease makes a site-specific double-stranded break at MAT, the yeast mating type locus. To identify other proteins involved in this process, we examined whether extracts prepared from ho- mutants contain additional factors that bind near the recognition sequence for Ho. Using an electrophoretic mobility shift assay, we isolated a chromatographic fraction that contains an activity, named YZbp, which binds to two sequences flanking the recognition sequence at MATalpha and to one sequence overlapping it at MATa. MAT plasmids carrying mutations in the YZbp recognition sequence are cleaved by purified Ho at wild-type efficiencies in an in vitro assay. These same plasmids, however, are not cleaved by Ho inside cells, demonstrating that YZbp acts as a positive activator of in vivo cleavage. YZbp is present in all cell types, even those not undergoing mating type switching, suggesting that it has additional cellular functions.

scholarly journals Mating type-like conversion promoted by the 2 micrograms circle site-specific recombinase: implications for the double-strand-gap repair model.

1986 ◽  
Vol 6 (11) ◽  
pp. 3831-3837 ◽  
Author(s):  
M Jayaram
Keyword(s):  
Mating Type ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Site Specific ◽  
Strand Breaks ◽  
Conversion Event ◽  
Yeast Mating ◽  
Mating Type Switching

Double-strand breaks in DNA are known to promote recombination in Saccharomyces cerevisiae. Yeast mating type switching, which is a highly efficient gene conversion event, is apparently initiated by a site-specific double-strand break. The 2 micrograms circle site-specific recombinase, FLP, has been shown to make double-strand breaks in its substrate DNA. By using a hybrid 2 micrograms circle::Tn5 plasmid, a portion of which resembles, in its DNA organization, the active (MAT) and the silent (HML) yeast mating type loci, it is shown that FLP mediates a conversion event analogous to mating type switching. Whereas the FLP site-specific recombination is not dependent on the RAD52 gene product, the FLP-induced conversion is abolished in a rad52 background. The FLP-promoted conversion in vivo can be faithfully reproduced by making a double-stranded gap in vitro in the vicinity of the FLP site and allowing the gap to be repaired in vivo.

Mating type-like conversion promoted by the 2 micrograms circle site-specific recombinase: implications for the double-strand-gap repair model

1986 ◽  
Vol 6 (11) ◽  
pp. 3831-3837
Author(s):  
M Jayaram
Keyword(s):  
Mating Type ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Site Specific ◽  
Strand Breaks ◽  
Conversion Event ◽  
Yeast Mating ◽  
Mating Type Switching

Double-strand breaks in DNA are known to promote recombination in Saccharomyces cerevisiae. Yeast mating type switching, which is a highly efficient gene conversion event, is apparently initiated by a site-specific double-strand break. The 2 micrograms circle site-specific recombinase, FLP, has been shown to make double-strand breaks in its substrate DNA. By using a hybrid 2 micrograms circle::Tn5 plasmid, a portion of which resembles, in its DNA organization, the active (MAT) and the silent (HML) yeast mating type loci, it is shown that FLP mediates a conversion event analogous to mating type switching. Whereas the FLP site-specific recombination is not dependent on the RAD52 gene product, the FLP-induced conversion is abolished in a rad52 background. The FLP-promoted conversion in vivo can be faithfully reproduced by making a double-stranded gap in vitro in the vicinity of the FLP site and allowing the gap to be repaired in vivo.

scholarly journals Investigation of Mating Pheromone–Pheromone Receptor Specificity in Lentinula edodes

Genes ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 506
Author(s):  
Sinil Kim ◽  
Byeongsuk Ha ◽  
Minseek Kim ◽  
Hyeon-Su Ro
Keyword(s):  
Mating Type ◽  
Lentinula Edodes ◽  
Signal Pathway ◽  
Recombinant Yeast ◽  
Mating Pheromone ◽  
Type Locus ◽  
Pheromone Receptor ◽  
Mating Type Locus ◽  
Yeast Mating ◽  
Mating Signal

The B mating-type locus of Lentinula edodes, a representative edible mushroom, is highly complex because of allelic variations in the mating pheromone receptors (RCBs) and the mating pheromones (PHBs) in both the Bα and Bβ subloci. The complexity of the B mating-type locus, five Bα subloci with five alleles of RCB1 and nine PHBs and three Bβ subloci with 3 alleles of RCB2 and five PHBs, has led us to investigate the specificity of the PHB–RCB interaction because the interaction plays a key role in non-self-recognition. In this study, the specificities of PHBs to RCB1-2 and RCB1-4 from the Bα sublocus and RCB2-1 from the Bb sublocus were investigated using recombinant yeast strains generated by replacing STE2, an endogenous yeast mating pheromone receptor, with the L. edodes RCBs. Fourteen synthetic PHBs with C-terminal carboxymethylation but without farnesylation were added to the recombinant yeast cells and the PHB–RCB interaction was monitored by the expression of the FUS1 gene—a downstream gene of the yeast mating signal pathway. RCB1-2 (Bα2) was activated by PHB1 (4.3-fold) and PHB2 (2.1-fold) from the Bα1 sublocus and RCB1-4 (Bα4) was activated by PHB5 (3.0-fold) and PHB6 (2.7-fold) from the Bα2 sublocus and PHB13 (3.0-fold) from the Bα5 sublocus. In particular, PHB3 from Bβ2 and PHB9 from Bβ3 showed strong activation of RCB2-1 of the Bβ1 sublocus by 59-fold. The RCB–PHB interactions were confirmed in the monokaryotic S1–10 strain of L. edodes by showing increased expression of clp1, a downstream gene of the mating signal pathway and the occurrence of clamp connections after the treatment of PHBs. These results indicate that a single PHB can interact with a non-self RCB in a sublocus-specific manner for the activation of the mating pheromone signal pathways in L. edodes.

scholarly journals Deletion of a Yci1 Domain Protein ofCandida albicansAllows Homothallic Mating inMTLHeterozygous Cells

mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Yuan Sun ◽  
Christine Gadoury ◽  
Matthew P. Hirakawa ◽  
Richard J. Bennett ◽  
Doreen Harcus ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Mating Type ◽  
Transcriptional Profiling ◽  
Mammalian Host ◽  
Epigenetic Switch ◽  
Type Locus ◽  
Human Fungal Pathogen ◽  
Mating Type Locus ◽  
New Gene

ABSTRACTIt has been proposed that the ancestral fungus was mating competent and homothallic. However, many mating-competent fungi were initially classified as asexual because their mating capacity was hidden behind layers of regulation. For efficientin vitromating, the essentially obligate diploid ascomycete pathogenCandida albicanshas to change its mating type locus from heterozygousMTLa/α to homozygousMTLa/aorMTLα/α and then undergo an environmentally controlled epigenetic switch to the mating-competent opaque form. These requirements greatly reduce the potential forC. albicansmating. Deletion of the Yci1 domain geneOFR1bypasses the need forC. albicanscells to change the mating type locus from heterozygous to homozygous prior to switching to the opaque form and mating and allows homothallic mating ofMTLheterozygous strains. This bypass is carbon source dependent and does not occur when cells are grown on glucose. Transcriptional profiling ofofr1mutant cells shows that in addition to regulating cell type and mating circuitry, Ofr1 is needed for proper regulation of histone and chitin biosynthesis gene expression. It appears thatOFR1is a key regulator inC. albicansand functions in part to maintain the cryptic mating phenotype of the pathogen.IMPORTANCECandida albicansis a human fungal pathogen with a recently discovered, highly cryptic mating ability. For efficient mating, it has to lose heterozygosity at its mating type locus. Then,MTLhomozygous strains can undergo an epigenetic switch to an elongated yeast state, termed the opaque form, and become mating competent. This infrequent two-step process greatly reduces the potential for mating; few strains areMTLhomozygous, and the opaque state is unstable at the temperature of the mammalian host.C. albicanshas a complex mechanism for mating that appears designed to ensure that mating is infrequent. Here, we have characterized a new gene, opaque-formation regulator 1 (OFR1). Deleting theOFR1gene allowsMTLa/α strains to mate efficiently with either mating type or even mate homothallically. It is possible that downregulatingOFR1in the host environment could allow mating inC. albicansby a route that does not involveMTLhomozygosis.

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.

RAP-1 factor is necessary for DNA loop formation in vitro at the silent mating type locus HML

Cell ◽  
1989 ◽  
Vol 57 (5) ◽  
pp. 725-737 ◽  
Author(s):  
Johannes F.-X. Hofmann ◽  
Thierry Laroche ◽  
Andrea H. Brand ◽  
Susan M. Gasser
Keyword(s):  
Mating Type ◽  
Loop Formation ◽  
Type Locus ◽  
Mating Type Locus ◽  
Dna Loop

Homology and non-homology at the yeast mating type locus

Nature ◽  
1981 ◽  
Vol 289 (5795) ◽  
pp. 250-252 ◽  
Author(s):  
George F. Sprague ◽  
Jasper Rine ◽  
Ira Herskowitz
Keyword(s):  
Mating Type ◽  
Type Locus ◽  
Mating Type Locus ◽  
Yeast Mating

scholarly journals Impact of Mating Type, Serotype, and Ploidy on the Virulence of Cryptococcus neoformans

2008 ◽  
Vol 76 (7) ◽  
pp. 2923-2938 ◽  
Author(s):  
Xiaorong Lin ◽  
Kirsten Nielsen ◽  
Sweta Patel ◽  
Joseph Heitman
Keyword(s):  
Cryptococcus Neoformans ◽  
Mating Type ◽  
Pathogenic Fungi ◽  
Mating Types ◽  
Type Locus ◽  
Virulence Potential ◽  
The Impact ◽  
Ad Hybrids

ABSTRACT Hybridization with polyploidization is a significant biological force driving evolution. The effect of combining two distinct genomes in one organism on the virulence potential of pathogenic fungi is not clear. Cryptococcus neoformans, the most common cause of fungal infection of the central nervous system, has a bipolar mating system with a and α mating types and occurs as A (haploid), D (haploid), and AD hybrid (mostly diploid) serotypes. Diploid AD hybrids are derived either from a-α mating or from unisexual mating between haploid cells. The precise contributions of increased ploidy, the effect of hybridization between serotypes A and D, and the combination of mating types to the virulence potential of AD hybrids have remained elusive. By using in vitro and in vivo characterization of laboratory-constructed isogenic diploids and AD hybrids with all possible mating type combinations in defined genetic backgrounds, we found that higher ploidy has a minor negative effect on virulence in a murine inhalation model of cryptococcosis. The presence of both mating types a and α in AD hybrids did not affect the virulence potential, irrespective of the serotype origin. Interestingly, AD hybrids with only one mating type behaved differently, with the virulence of αADα strains similar to that of other hybrids, while aADa hybrids displayed significantly lower virulence due to negative epistatic interactions between the Aa and Da alleles of the mating type locus. This study provides insights into the impact of ploidy, mating type, and serotype on virulence and the impact of hybridization on the fitness and virulence of a eukaryotic microbial pathogen.

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