scholarly journals The Conformation of Yeast Chromosome III Is Mating Type Dependent and Controlled by the Recombination Enhancer

Cell Reports ◽  
2015 ◽  
Vol 13 (9) ◽  
pp. 1855-1867 ◽  
Author(s):  
Jon-Matthew Belton ◽  
Bryan R. Lajoie ◽  
Sylvain Audibert ◽  
Sylvain Cantaloube ◽  
Imen Lassadi ◽  
...  
Keyword(s):  
Mating Type ◽  
Yeast Chromosome ◽  
Chromosome Iii ◽  
Recombination Enhancer

Isolation of a circular derivative of yeast chromosome III: implications for the mechanism of mating type interconversion

Cell ◽  
1979 ◽  
Vol 18 (2) ◽  
pp. 309-319 ◽  
Author(s):  
Jeffrey N. Strathern ◽  
Carol S. Newlon ◽  
Ira Herskowitz ◽  
James B. Hicks
Keyword(s):  
Mating Type ◽  
Yeast Chromosome ◽  
Chromosome Iii

scholarly journals A Sir2-regulated locus control region in the recombination enhancer of Saccharomyces cerevisiae specifies chromosome III structure

2019 ◽  
Author(s):  
Mingguang Li ◽  
Ryan D. Fine ◽  
Manikarna Dinda ◽  
Stefan Bekiranov ◽  
Jeffrey S. Smith
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Control Region ◽  
Mating Type ◽  
Locus Control Region ◽  
A Cells ◽  
Mating Type Switching ◽  
Chromosome Iii ◽  
The Right ◽  
Donor Preference ◽  
Recombination Enhancer

AbstractThe NAD+-dependent histone deacetylase Sir2 was originally identified in Saccharomyces cerevisiae as a silencing factor for HML and HMR, the heterochromatic cassettes utilized as donor templates during mating-type switching. MATa cells preferentially switch to MATα using HML as the donor, which is driven by an adjacent cis-acting element called the recombination enhancer (RE). In this study we demonstrate that Sir2 and the condensin complex are recruited to the RE exclusively in MATa cells, specifically to the promoter of a small gene within the right half of the RE known as RDT1. We go on to demonstrate that the RDT1 promoter functions as a locus control region (LCR) that regulates both transcription and long-range chromatin interactions. Sir2 represses the transcription of RDT1 until it is redistributed to a dsDNA break at the MAT locus induced by the HO endonuclease during mating-type switching. Condensin is also recruited to the RDT1 promoter and is displaced upon HO induction, but does not significantly repress RDT1 transcription. Instead condensin appears to promote mating-type switching efficiency and donor preference by maintaining proper chromosome III architecture, which is defined by the interaction of HML with the right arm of chromosome III, including MATa and HMR. Remarkably, eliminating Sir2 and condensin recruitment to the RDT1 promoter disrupts this structure and reveals an aberrant interaction between MATa and HMR, consistent with the partially defective donor preference for this mutant. Global condensin subunit depletion also impairs mating type switching efficiency and donor preference, suggesting that modulation of chromosome architecture plays a significant role in controlling mating type switching, thus providing a novel model for dissecting condensin function in vivo.Author summarySir2 is a highly conserved NAD+-dependent protein deacetylase and defining member of the sirtuin protein family. It was identified about 40 years ago in the budding yeast, Saccharomyces cerevisiae, as a gene required for silencing of the cryptic mating-type loci, HML and HMR. These heterochromatic cassettes are utilized as templates for mating-type switching, whereby a programmed DNA double-strand break at the MATa or MATα locus is repaired by gene conversion to the opposite mating type. The preference for switching to the opposite mating type is called donor preference, and in MATa cells, is driven by a cis-acting DNA element called the recombination enhancer (RE). It was believed that the only role for Sir2 in mating-type switching was silencing HML and HMR. However, in this study we show that Sir2 also regulates expression of a small gene (RDT1) in the RE that is activated during mating-type switching. The promoter of this gene is also bound by the condensin complex, and deleting this region of the RE drastically changes chromosome III structure and alters donor preference. The RE therefore appears to function as a complex locus control region (LCR) that links transcriptional control to chromatin architecture, and thus provides a new model for investigating the underlying mechanistic principles of programmed chromosome architectural dynamics.

scholarly journals Global Chromatin Structure of 45,000 Base Pairs of Chromosome III in a- and α-Cell Yeast and during Mating-Type Switching

2004 ◽  
Vol 24 (22) ◽  
pp. 10026-10035 ◽  
Author(s):  
Sevinc Ercan ◽  
Robert T. Simpson
Keyword(s):  
Mating Type ◽  
Chromatin Structure ◽  
Cell Types ◽  
Open Reading Frames ◽  
Base Pairs ◽  
Distinctive Features ◽  
Hypersensitive Sites ◽  
Mating Type Switching ◽  
Chromosome Iii ◽  
Recombination Enhancer

ABSTRACT Directionality of yeast mating-type switching has been attributed to differences in chromatin structure for the left arm of chromosome III. We have mapped the structure of ∼45 kbp of the left arm of chromosome III in a and α cells in logarithmically growing cultures and in a cells during switching. Distinctive features of chromatin structure were the occurrence of DNase I-hypersensitive sites in the promoter region of nearly every gene and some replication origins and the presence of extended regions of positioned nucleosomes in ∼25% of the open reading frames. Other than the recombination enhancer, chromatin structures were identical in the two cell types. Changes in chromatin structure during switching were confined to the recombination enhancer. This unbiased analysis of an extended region of chromatin reveals that significant features of organized chromatin exist for the entire region, and these features are largely static with respect to mating type and mating-type switching. Our analysis also shows that primary chromatin structure does not cause the documented differences in recombinational frequency of the left arm of chromosome III in yeast a and α cells.

scholarly journals Mating type–dependent constraints on the mobility of the left arm of yeast chromosome III

2004 ◽  
Vol 164 (3) ◽  
pp. 361-371 ◽  
Author(s):  
Debra A. Bressan ◽  
Julio Vazquez ◽  
James E. Haber
Keyword(s):  
Mating Type ◽  
Three Dimensional ◽  
Cell Mobility ◽  
Yeast Chromosome ◽  
Mating Type Gene ◽  
Type Gene ◽  
Three Dimensional Configuration ◽  
Chromosome Iii ◽  
The Right ◽  
Donor Preference

Mating-type gene (MAT) switching in budding yeast exhibits donor preference. MATa preferentially recombines with HML near the left telomere of chromosome III, whereas MATα prefers HMR near the right telomere. Donor preference is controlled by the recombination enhancer (RE) located proximal to HML. To test if HML is constrained in pairing with MATα, we examined live-cell mobility of LacI-GFP–bound lactose operator (lacO) arrays inserted at different chromosomal sites. Without induction of recombination, lacO sequences adjacent to HML are strongly constrained in both MATα and RE-deleted MATa strains, compared with MATa. In contrast, chromosome movement at HMR or near a telomere of chromosome V is mating-type independent. HML is more constrained in MATa Δre and less constrained in MATa RE+ compared with other sites. Although HML and MATa are not prealigned before inducing recombination, the three-dimensional configuration of MAT, HML, and HMR is mating-type dependent. These data suggest there is constitutive tethering of HML, which is relieved in MATa cells through the action of RE.

Homothallic mating type switching generates lethal chromosome breaks in rad52 strains of Saccharomyces cerevisiae

1981 ◽  
Vol 1 (6) ◽  
pp. 522-534
Author(s):  
B Weiffenbach ◽  
J E Haber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Deoxyribonucleic Acid ◽  
Type Locus ◽  
Mating Type Switching ◽  
Lethal Event ◽  
Bona Fide ◽  
Chromosome Iii ◽  
Mat Locus ◽  
Type Information

In homothallic cells of Saccharomyces cerevisiae, a or alpha mating type information at the mating type locus (MAT) is replaced by the transposition of the opposite mating type allele from HML alpha or HMRa. The rad52-1 mutation, which reduces mitotic and abolishes meiotic recombination, also affects homothallic switching (Malone and Esposito, Proc. Natl. Acad. Sci. U.S.A. 77:503-507, 1980). We have found that both HO rad52 MATa and HO rad52 MAT alpha cells die. This lethality is suppressed by mutations that substantially reduce but do not eliminate homothallic conversions. These mutations map at or near the MAT locus (MAT alpha inc, MATa-inc, MATa stk1) or are unlinked to MAT (HO-1 and swi1). These results suggest that the switching event itself is involved in the lethality. With the exception of swi1, HO rad52 strains carrying one of the above mutations cannot convert mating type at all. MAT alpha rad52 HO swi1 strains apparently can switch MAT alpha to MATa. However, when we analyzed these a maters, we found that few, if any, of them were bona fide MATa cells. These a-like cells were instead either deleted for part of chromosome III distal to and including MAT or had lost the entire third chromosome. Approximately 30% of the time, an a-like cell could be repaired to a normal MATa genotype if the cell was mated to a RAD52 MAT alpha-inc strain. The effects of rad52 were also studied in mata/MAT alpha-inc rad52/rad52 ho/HO diploids. When this diploid attempted to switch mata to MATa, an unstable broken chromosome was generated in nearly every cell. These studies suggest that homothallic switching involves the formation of a double-stranded deoxyribonucleic acid break or a structure which is labile in rad52 cells and results in a broken chromosome. We propose that the production of a double-stranded deoxyribonucleic acid break is the lethal event in rad52 HO cells.

Expansions and contractions of the genetic map relative to the physical map of yeast chromosome III

1988 ◽  
Vol 8 (2) ◽  
pp. 595-604
Author(s):  
L S Symington ◽  
T D Petes
Keyword(s):  
Gene Conversion ◽  
Restriction Site ◽  
Physical Map ◽  
Minimum Length ◽  
Base Pairs ◽  
Yeast Saccharomyces Cerevisiae ◽  
Yeast Chromosome ◽  
Chromosome Maps ◽  
Chromosome Iii ◽  
The Relationship

To examine the relationship between genetic and physical chromosome maps, we constructed a diploid strain of the yeast Saccharomyces cerevisiae heterozygous for 12 restriction site mutations within a 23-kilobase (5-centimorgan) interval of chromosome III. Crossovers were not uniformly distributed along the chromosome, one interval containing significantly more and one interval significantly fewer crossovers than expected. One-third of these crossovers occurred within 6 kilobases of the centromere. Approximately half of the exchanges were associated with gene conversion events. The minimum length of gene conversion tracts varied from 4 base pairs to more than 12 kilobases, and these tracts were nonuniformly distributed along the chromosome. We conclude that the chromosomal sequence or structure has a dramatic effect on meiotic recombination.

The HML mating-type cassette of Saccharomyces cerevisiae is regulated by two separate but functionally equivalent silencers

1989 ◽  
Vol 9 (11) ◽  
pp. 4621-4630
Author(s):  
D J Mahoney ◽  
J R Broach
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Binding Sites ◽  
The Other ◽  
Functional Domains ◽  
Gene Products ◽  
Cis Acting ◽  
Full Expression ◽  
Mating Type Genes ◽  
Chromosome Iii

Mating-type genes resident in the silent cassette HML at the left arm of chromosome III are repressed by the action of four SIR gene products, most likely mediated through two cis-acting sites located on opposite sides of the locus. We showed that deletion of either of these two cis-acting sites from the chromosome did not yield any detectable derepression of HML, while deletion of both sites yielded full expression of the locus. In addition, each of these sites was capable of exerting repression of heterologous genes inserted in their vicinity. Thus, HML expression is regulated by two independent silencers, each fully competent for maintaining repression. This situation was distinct from the organization of the other silent locus, HMR, at which a single silencer served as the predominant repressor of expression. Examination of identifiable domains and binding sites within the HML silencers suggested that silencing activity can be achieved by a variety of combinations of various functional domains.

Functional domains of SIR4, a gene required for position effect regulation in Saccharomyces cerevisiae

1987 ◽  
Vol 7 (12) ◽  
pp. 4441-4452
Author(s):  
M Marshall ◽  
D Mahoney ◽  
A Rose ◽  
J B Hicks ◽  
J R Broach
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Position Effect ◽  
Protein Activity ◽  
Multicomponent Complex ◽  
Mating Type Genes ◽  
Chromosome Iii ◽  
Covalently Linked ◽  
High Level ◽  
Mat Locus

The product of the Saccharomyces cerevisiae SIR4 gene, in conjunction with at least three other gene products, prevents expression of mating-type genes resident at loci at either end of chromosome III, but not of the same genes resident at the MAT locus in the middle of the chromosome. To address the mechanism of this novel position effect regulation, we have conducted a structural and genetic analysis of the SIR4 gene. We have determined the nucleotide sequence of the gene and found that it encodes a lysine-rich, serine-rich protein of 152 kilodaltons. Expression of the carboxy half of the protein complements a chromosomal nonsense mutation of sir4 but not a complete deletion of the gene. These results suggest that SIR4 protein activity resides in two portions of the molecule, but that these domains need not be covalently linked to execute their biological function. We also found that high-level expression of the carboxy domain of the protein yields dominant derepression of the silent loci. This anti-Sir activity can be reversed by increased expression of the SIR3 gene, whose product is normally also required for maintaining repression of the silent loci. These results are consistent with the hypothesis that SIR3 and SIR4 proteins physically associate to form a multicomponent complex required for repression of the silent mating-type loci.

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