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Lim KK, Lam UTF, Li Y, Zeng YB, Yang H, Chen ES. Set2 regulates Ccp1 and Swc2 to ensure centromeric stability by retargeting CENP-A. Nucleic Acids Res 2024; 52:4198-4214. [PMID: 38442274 PMCID: PMC11077061 DOI: 10.1093/nar/gkae084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 01/24/2024] [Accepted: 01/29/2024] [Indexed: 03/07/2024] Open
Abstract
Precise positioning of the histone-H3 variant, CENP-A, ensures centromere stability and faithful chromosomal segregation. Mislocalization of CENP-A to extra-centromeric loci results in aneuploidy and compromised cell viability associated with formation of ectopic kinetochores. The mechanism that retargets mislocalized CENP-A back to the centromere is unclarified. We show here that the downregulation of the histone H3 lysine 36 (H3K36) methyltransferase Set2 can preserve centromere localization of a temperature-sensitive mutant cnp1-1 Schizosaccharomyces pombe CENP-A (SpCENP-A) protein and reverse aneuploidy by redirecting mislocalized SpCENP-A back to centromere from ribosomal DNA (rDNA) loci, which serves as a sink for the delocalized SpCENP-A. Downregulation of set2 augments Swc2 (SWR1 complex DNA-binding module) expression and releases histone chaperone Ccp1 from the centromeric reservoir. Swc2 and Ccp1 are directed to the rDNA locus to excavate the SpCENP-Acnp1-1, which is relocalized to the centromere in a manner dependent on canonical SpCENP-A loaders, including Mis16, Mis17 and Mis18, thereby conferring cell survival and safeguarding chromosome segregation fidelity. Chromosome missegregation is a severe genetic instability event that compromises cell viability. This mechanism thus promotes CENP-A presence at the centromere to maintain genomic stability.
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Affiliation(s)
- Kim Kiat Lim
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ulysses Tsz Fung Lam
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ying Li
- NUS Center for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Cancer Science Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Yi Bing Zeng
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Henry Yang
- NUS Center for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Cancer Science Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- National University Health System, Singapore
| | - Ee Sin Chen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- NUS Center for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- National University Health System, Singapore
- Integrative Sciences & Engineering Programme, National University of Singapore, Singapore
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Lim KK, Koh NZH, Zeng YB, Chuan JK, Raechell R, Chen ES. Resistance to Chemotherapeutic 5-Fluorouracil Conferred by Modulation of Heterochromatic Integrity through Ino80 Function in Fission Yeast. Int J Mol Sci 2023; 24:10687. [PMID: 37445861 DOI: 10.3390/ijms241310687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/23/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023] Open
Abstract
5-Fluorouracil (5-FU) is a conventional chemotherapeutic drug widely used in clinics worldwide, but development of resistance that compromises responsiveness remains a major hurdle to its efficacy. The mechanism underlying 5-FU resistance is conventionally attributed to the disruption of nucleotide synthesis, even though research has implicated other pathways such as RNA processing and chromatin dysregulation. Aiming to clarify resistance mechanisms of 5-FU, we tested the response of a collection of fission yeast (Schizosaccharomyces pombe) null mutants, which confer multiple environmental factor responsiveness (MER). Our screen identified disruption of membrane transport, chromosome segregation and mitochondrial oxidative phosphorylation to increase cellular susceptibility towards 5-FU. Conversely, we revealed several null mutants of Ino80 complex factors exhibited resistance to 5-FU. Furthermore, attenuation of Ino80 function via deleting several subunit genes reversed loss of chromosome-segregation fidelity in 5-FU in the loss-of-function mutant of the Argonaute protein, which regulates RNA interference (RNAi)-dependent maintenance of pericentromeric heterochromatin. Our study thus uncovered a critical role played by chromatin remodeling Ino80 complex factors in 5-FU resistance, which may constitute a possible target to modulate in reversing 5-FU resistance.
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Affiliation(s)
- Kim Kiat Lim
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Nathaniel Zhi Hao Koh
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Yi Bing Zeng
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Jun Kai Chuan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Raechell Raechell
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| | - Ee Sin Chen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
- National University Health System (NUHS), Singapore 119228, Singapore
- NUS Center for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore
- NUS Graduate School-Integrative Sciences & Engineering Programme, National University of Singapore, Singapore 119077, Singapore
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Chen ES. Application of the fission yeast Schizosaccharomyces pombe in human nutrition. FEMS Yeast Res 2023; 23:6961766. [PMID: 36574952 DOI: 10.1093/femsyr/foac064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/03/2022] [Accepted: 12/26/2022] [Indexed: 12/29/2022] Open
Abstract
Fission yeast Schizosaccharomyces pombe (S. pombe) is renowned as a powerful genetic model for deciphering cellular and molecular biological phenomena, including cell division, chromosomal events, stress responses, and human carcinogenesis. Traditionally, Africans use S. pombe to ferment the beer called 'Pombe', which continues to be consumed in many parts of Africa. Although not as widely utilized as the baker's yeast Saccharomyces cerevisiae, S. pombe has secured several niches in the food industry for human nutrition because of its unique metabolism. This review will explore three specific facets of human nutrition where S. pombe has made a significant impact: namely, in wine fermentation, animal husbandry and neutraceutical supplementation coenzyme Q10 production. Discussions focus on the current gaps in these areas, and the potential research advances useful for addressing future challenges. Overall, gaining a better understanding of S. pombe metabolism will strengthen production in these areas and potentially spearhead novel future applications.
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Affiliation(s)
- Ee Sin Chen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore.,National University Health System (NUHS), Singapore 119228, Singapore.,NUS Center for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117599, Singapore
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GRANT Motif Regulates CENP-A Incorporation and Restricts RNA Polymerase II Accessibility at Centromere. Genes (Basel) 2022; 13:genes13101697. [PMID: 36292582 PMCID: PMC9602348 DOI: 10.3390/genes13101697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/10/2022] [Accepted: 09/12/2022] [Indexed: 11/24/2022] Open
Abstract
Precise chromosome segregation is essential for maintaining genomic stability, and its proper execution centers on the centromere, a chromosomal locus that mounts the kinetochore complex to mediate attachment of chromosomes to the spindle microtubules. The location of the centromere is epigenetically determined by a centromere-specific histone H3 variant, CENP-A. Many human cancers exhibit overexpression of CENP-A, which correlates with occurrence of aneuploidy in these malignancies. Centromeric targeting of CENP-A depends on its histone fold, but recent studies showed that the N-terminal tail domain (NTD) also plays essential roles. Here, we investigated implications of NTD in conferring aneuploidy formation when CENP-A is overexpressed in fission yeast. A series of mutant genes progressively lacking one amino acid of the NTD have been constructed for overexpression in wild-type cells using the intermediate strength nmt41 promoter. Constructs hosting disrupted GRANT (Genomic stability-Regulating site within CENP-A N-Terminus) motif in NTD results in growth retardation, aneuploidy, increased localization to the centromere, upregulated RNA polymerase II accessibility and transcriptional derepression of the repressive centromeric chromatin, suggesting that GRANT residues fine-tune centromeric CENP-A incorporation and restrict RNA polymerase II accessibility. This work highlighted the importance of CENP-A NTD, particularly the GRANT motif, in aneuploidy formation of overexpressed CENP-A in fission yeast.
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Cavalieri V. The Expanding Constellation of Histone Post-Translational Modifications in the Epigenetic Landscape. Genes (Basel) 2021; 12:genes12101596. [PMID: 34680990 PMCID: PMC8535662 DOI: 10.3390/genes12101596] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/02/2021] [Accepted: 10/05/2021] [Indexed: 12/17/2022] Open
Abstract
The emergence of a nucleosome-based chromatin structure accompanied the evolutionary transition from prokaryotes to eukaryotes. In this scenario, histones became the heart of the complex and precisely timed coordination between chromatin architecture and functions during adaptive responses to environmental influence by means of epigenetic mechanisms. Notably, such an epigenetic machinery involves an overwhelming number of post-translational modifications at multiple residues of core and linker histones. This review aims to comprehensively describe old and recent evidence in this exciting field of research. In particular, histone post-translational modification establishing/removal mechanisms, their genomic locations and implication in nucleosome dynamics and chromatin-based processes, as well as their harmonious combination and interdependence will be discussed.
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Affiliation(s)
- Vincenzo Cavalieri
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90128 Palermo, Italy
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Fission Yeast Methylenetetrahydrofolate Reductase Ensures Mitotic and Meiotic Chromosome Segregation Fidelity. Int J Mol Sci 2021; 22:ijms22020639. [PMID: 33440639 PMCID: PMC7827777 DOI: 10.3390/ijms22020639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 01/05/2021] [Indexed: 12/17/2022] Open
Abstract
Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the folate metabolic pathway, and its loss of function through polymorphisms is often associated with human conditions, including cancer, congenital heart disease, and Down syndrome. MTHFR is also required in the maintenance of heterochromatin, a crucial determinant of genomic stability and precise chromosomal segregation. Here, we characterize the function of a fission yeast gene met11+, which encodes a protein that is highly homologous to the mammalian MTHFR. We show that, although met11+ is not essential for viability, its disruption increases chromosome missegregation and destabilizes constitutive heterochromatic regions at pericentromeric, sub-telomeric and ribosomal DNA (rDNA) loci. Transcriptional silencing at these sites were disrupted, which is accompanied by the reduction in enrichment of histone H3 lysine 9 dimethylation (H3K9me2) and binding of the heterochromatin protein 1 (HP1)-like Swi6. The met11 null mutant also dominantly disrupts meiotic fidelity, as displayed by reduced sporulation efficiency and defects in proper partitioning of the genetic material during meiosis. Interestingly, the faithful execution of these meiotic processes is synergistically ensured by cooperation among Met11, Rec8, a meiosis-specific cohesin protein, and the shugoshin protein Sgo1, which protects Rec8 from untimely cleavage. Overall, our results suggest a key role for Met11 in maintaining pericentromeric heterochromatin for precise genetic inheritance during mitosis and meiosis.
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N-Terminus Does Not Govern Protein Turnover of Schizosaccharomyces pombe CENP-A. Int J Mol Sci 2020; 21:ijms21176175. [PMID: 32859127 PMCID: PMC7503380 DOI: 10.3390/ijms21176175] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/18/2020] [Accepted: 08/21/2020] [Indexed: 12/15/2022] Open
Abstract
Centromere integrity underlies an essential framework for precise chromosome segregation and epigenetic inheritance. Although centromeric DNA sequences vary among different organisms, all eukaryotic centromeres comprise a centromere-specific histone H3 variant, centromeric protein A (CENP-A), on which other centromeric proteins assemble into the kinetochore complex. This complex connects chromosomes to mitotic spindle microtubules to ensure accurate partitioning of the genome into daughter cells. Overexpression of CENP-A is associated with many cancers and is correlated with its mistargeting, forming extra-centromeric kinetochore structures. The mislocalization of CENP-A can be counteracted by proteolysis. The amino (N)-terminal domain (NTD) of CENP-A has been implicated in this regulation and shown to be dependent on the proline residues within this domain in Saccharomyces cerevisiae CENP-A, Cse4. We recently identified a proline-rich GRANT motif in the NTD of Schizosaccharomyces pombe CENP-A (SpCENP-A) that regulates the centromeric targeting of CENP-A via binding to the CENP-A chaperone Sim3. Here, we investigated whether the NTD is required to confer SpCENP-A turnover (i.e., counter stability) using various truncation mutants of SpCENP-A. We show that sequential truncation of the NTD did not improve the stability of the protein, indicating that the NTD of SpCENP-A does not drive turnover of the protein. Instead, we reproduced previous observations that heterochromatin integrity is important for SpCENP-A stability, and showed that this occurs in an NTD-independent manner. Cells bearing the null mutant of the histone H3 lysine 9 methyltransferase Clr4 (Δclr4), which have compromised constitutive heterochromatin integrity, showed reductions in the proportion of SpCENP-A in the chromatin-containing insoluble fraction of the cell extract, suggesting that heterochromatin may promote SpCENP-A chromatin incorporation. Thus, a disruption in heterochromatin may result in the delocalization of SpCENP-A from chromatin, thus exposing it to protein turnover. Taken together, we show that the NTD is not required to confer SpCENP-A protein turnover.
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Takayama Y. Identification of Genes Encoding CENP-A and Heterochromatin Protein 1 of Lipomyces starkeyi and Functional Analysis Using Schizosaccharomyces pombe. Genes (Basel) 2020; 11:genes11070769. [PMID: 32650514 PMCID: PMC7397231 DOI: 10.3390/genes11070769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/06/2020] [Accepted: 07/06/2020] [Indexed: 11/16/2022] Open
Abstract
Centromeres function as a platform for the assembly of multiple kinetochore proteins and are essential for chromosome segregation. An active centromere is characterized by the presence of a centromere-specific histone H3 variant, CENP-A. Faithful centromeric localization of CENP-A is supported by heterochromatin in almost all eukaryotes; however, heterochromatin proteins have been lost in most Saccharomycotina. Here, identification of CENP-A (CENP-AL.s.) and heterochromatin protein 1 (Lsw1) in a Saccharomycotina species, the oleaginous yeast Lipomyces starkeyi, is reported. To determine if these proteins are functional, the proteins in S. pombe, a species widely used to study centromeres, were ectopically expressed. CENP-AL.s. localizes to centromeres and can be replaced with S. pombe CENP-A, indicating that CENP-AL.s. is a functional centromere-specific protein. Lsw1 binds at heterochromatin regions, and chromatin binding is dependent on methylation of histone H3 at lysine 9. In other species, self-interaction of heterochromatin protein 1 is thought to cause folding of chromatin, triggering transcription repression and heterochromatin formation. Consistent with this, it was found that Lsw1 can self-interact. L. starkeyi chromatin contains the methylation of histone H3 at lysine 9. These results indicated that L. starkeyi has a primitive heterochromatin structure and is an attractive model for analysis of centromere heterochromatin evolution.
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Affiliation(s)
- Yuko Takayama
- Department of Biosciences, School of Science and Engineering, Teikyo University, 1-1 Toyosatodai, Utsunomiya, Tochigi 320–8551, Japan; ; Tel.: +81-28-627-7242
- Division of Integrated Science and Engineering, Graduate School of Science and Engineering, Teikyo University Graduate Schools, 1–1 Toyosatodai, Utsunomiya, Tochigi 320–8551, Japan
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Le Goff S, Keçeli BN, Jeřábková H, Heckmann S, Rutten T, Cotterell S, Schubert V, Roitinger E, Mechtler K, Franklin FCH, Tatout C, Houben A, Geelen D, Probst AV, Lermontova I. The H3 histone chaperone NASP SIM3 escorts CenH3 in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 101:71-86. [PMID: 31463991 DOI: 10.1111/tpj.14518] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 08/16/2019] [Accepted: 08/21/2019] [Indexed: 06/10/2023]
Abstract
Centromeres define the chromosomal position where kinetochores form to link the chromosome to microtubules during mitosis and meiosis. Centromere identity is determined by incorporation of a specific histone H3 variant termed CenH3. As for other histones, escort and deposition of CenH3 must be ensured by histone chaperones, which handle the non-nucleosomal CenH3 pool and replenish CenH3 chromatin in dividing cells. Here, we show that the Arabidopsis orthologue of the mammalian NUCLEAR AUTOANTIGENIC SPERM PROTEIN (NASP) and Schizosaccharomyces pombe histone chaperone Sim3 is a soluble nuclear protein that binds the histone variant CenH3 and affects its abundance at the centromeres. NASPSIM3 is co-expressed with Arabidopsis CenH3 in dividing cells and binds directly to both the N-terminal tail and the histone fold domain of non-nucleosomal CenH3. Reduced NASPSIM3 expression negatively affects CenH3 deposition, identifying NASPSIM3 as a CenH3 histone chaperone.
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Affiliation(s)
- Samuel Le Goff
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001, Clermont-Ferrand, France
| | - Burcu Nur Keçeli
- Department of Plants and Crops, Unit HortiCell, Faculty of Bioscience Engineering, Ghent University, Coupure links, 653, 9000, Ghent, Belgium
| | - Hana Jeřábková
- The Czech Academy of Sciences, Institute of Experimental Botany (IEB), Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 31, 78 371, Olomouc, Czech Republic
| | - Stefan Heckmann
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, D-06466, Seeland, Germany
| | - Twan Rutten
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, D-06466, Seeland, Germany
| | - Sylviane Cotterell
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001, Clermont-Ferrand, France
| | - Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, D-06466, Seeland, Germany
| | - Elisabeth Roitinger
- Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, 1030, Austria
- Institute of Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, 1030, Austria
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, 1030, Austria
| | - Karl Mechtler
- Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, 1030, Austria
- Institute of Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, 1030, Austria
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, 1030, Austria
| | | | - Christophe Tatout
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001, Clermont-Ferrand, France
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, D-06466, Seeland, Germany
| | - Danny Geelen
- Department of Plants and Crops, Unit HortiCell, Faculty of Bioscience Engineering, Ghent University, Coupure links, 653, 9000, Ghent, Belgium
| | - Aline V Probst
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001, Clermont-Ferrand, France
| | - Inna Lermontova
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, D-06466, Seeland, Germany
- Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Brno, CZ-62500, Czech Republic
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Folco HD, McCue A, Balachandran V, Grewal SIS. Cohesin Impedes Heterochromatin Assembly in Fission Yeast Cells Lacking Pds5. Genetics 2019; 213:127-141. [PMID: 31278118 PMCID: PMC6727797 DOI: 10.1534/genetics.119.302256] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 06/24/2019] [Indexed: 01/05/2023] Open
Abstract
The fission yeast Schizosaccharomyces pombe is a powerful genetic model system for uncovering fundamental principles of heterochromatin assembly and epigenetic inheritance of chromatin states. Heterochromatin defined by histone H3 lysine 9 methylation and HP1 proteins coats large chromosomal domains at centromeres, telomeres, and the mating-type (mat) locus. Although genetic and biochemical studies have provided valuable insights into heterochromatin assembly, many key mechanistic details remain unclear. Here, we use a sensitized reporter system at the mat locus to screen for factors affecting heterochromatic silencing. In addition to known components of heterochromatin assembly pathways, our screen identified eight new factors including the cohesin-associated protein Pds5. We find that Pds5 enriched throughout heterochromatin domains is required for proper maintenance of heterochromatin. This function of Pds5 requires its associated Eso1 acetyltransferase, which is implicated in the acetylation of cohesin. Indeed, introducing an acetylation-mimicking mutation in a cohesin subunit suppresses defects in heterochromatin assembly in pds5∆ and eso1∆ cells. Our results show that in cells lacking Pds5, cohesin interferes with heterochromatin assembly. Supporting this, eliminating cohesin from the mat locus in the pds5∆ mutant restores both heterochromatin assembly and gene silencing. These analyses highlight an unexpected requirement for Pds5 in ensuring proper coordination between cohesin and heterochromatin factors to effectively maintain gene silencing.
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Affiliation(s)
- H Diego Folco
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Andrea McCue
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Vanivilasini Balachandran
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Shiv I S Grewal
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
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