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Nicolas Y, Bret H, Cannavo E, Acharya A, Cejka P, Borde V, Guerois R. Molecular insights into the activation of Mre11-Rad50 endonuclease activity by Sae2/CtIP. Mol Cell 2024; 84:2223-2237.e4. [PMID: 38870937 DOI: 10.1016/j.molcel.2024.05.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 02/25/2024] [Accepted: 05/20/2024] [Indexed: 06/15/2024]
Abstract
In Saccharomyces cerevisiae (S. cerevisiae), Mre11-Rad50-Xrs2 (MRX)-Sae2 nuclease activity is required for the resection of DNA breaks with secondary structures or protein blocks, while in humans, the MRE11-RAD50-NBS1 (MRN) homolog with CtIP is needed to initiate DNA end resection of all breaks. Phosphorylated Sae2/CtIP stimulates the endonuclease activity of MRX/N. Structural insights into the activation of the Mre11 nuclease are available only for organisms lacking Sae2/CtIP, so little is known about how Sae2/CtIP activates the nuclease ensemble. Here, we uncover the mechanism of Mre11 activation by Sae2 using a combination of AlphaFold2 structural modeling of biochemical and genetic assays. We show that Sae2 stabilizes the Mre11 nuclease in a conformation poised to cleave substrate DNA. Several designs of compensatory mutations establish how Sae2 activates MRX in vitro and in vivo, supporting the structural model. Finally, our study uncovers how human CtIP, despite considerable sequence divergence, employs a similar mechanism to activate MRN.
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Affiliation(s)
- Yoann Nicolas
- Institut Curie, PSL University, Sorbonne Université, CNRS UMR3244, Dynamics of Genetic Information, 75005 Paris, France
| | - Hélène Bret
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Elda Cannavo
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona 6500, Switzerland
| | - Ananya Acharya
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona 6500, Switzerland
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Bellinzona 6500, Switzerland.
| | - Valérie Borde
- Institut Curie, PSL University, Sorbonne Université, CNRS UMR3244, Dynamics of Genetic Information, 75005 Paris, France.
| | - Raphaël Guerois
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.
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Aithal R, Nangalia K, Spirek M, Chen D, Klein F, Krejci L. Physical interaction with Spo11 mediates the localisation of Mre11 to chromatin in meiosis and promotes its nuclease activity. Nucleic Acids Res 2024; 52:4328-4343. [PMID: 38407383 PMCID: PMC11077076 DOI: 10.1093/nar/gkae111] [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: 04/21/2023] [Revised: 01/19/2024] [Accepted: 02/06/2024] [Indexed: 02/27/2024] Open
Abstract
Meiotic recombination is of central importance for the proper segregation of homologous chromosomes, but also for creating genetic diversity. It is initiated by the formation of double-strand breaks (DSBs) in DNA catalysed by evolutionarily conserved Spo11, together with additional protein partners. Difficulties in purifying the Spo11 protein have limited the characterization of its biochemical properties and of its interactions with other DSB proteins. In this study, we have purified fragments of Spo11 and show for the first time that Spo11 can physically interact with Mre11 and modulates its DNA binding, bridging, and nuclease activities. The interaction of Mre11 with Spo11 requires its far C-terminal region, which is in line with the severe meiotic phenotypes of various mre11 mutations located at the C-terminus. Moreover, calibrated ChIP for Mre11 shows that Spo11 promotes Mre11 recruitment to chromatin, independent of DSB formation. A mutant deficient in Spo11 interaction severely reduces the association of Mre11 with meiotic chromatin. Consistent with the reduction of Mre11 foci in this mutant, it strongly impedes DSB formation, leading to spore death. Our data provide evidence that physical interaction between Spo11 and Mre11, together with end-bridging, promote normal recruitment of Mre11 to hotspots and DSB formation.
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Affiliation(s)
- Rakesh Aithal
- National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
- Department of Biology, Masaryk University, Brno, Czech Republic
| | - Kuldeep Nangalia
- Department of Chromosome Biology, Center for Molecular Biology, University of Vienna
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Dr.-Bohr-Gasse 9, 1030Vienna, Austria
| | - Mario Spirek
- Department of Biology, Masaryk University, Brno, Czech Republic
| | - Doris Chen
- Department of Chromosome Biology, Center for Molecular Biology, University of Vienna
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Dr.-Bohr-Gasse 9, 1030Vienna, Austria
| | - Franz Klein
- Department of Chromosome Biology, Center for Molecular Biology, University of Vienna
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Dr.-Bohr-Gasse 9, 1030Vienna, Austria
| | - Lumir Krejci
- National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
- Department of Biology, Masaryk University, Brno, Czech Republic
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Zhao J, Li X, Qiao L, Zheng X, Wu B, Guo M, Feng M, Qi Z, Yang W, Zheng J. Identification of structural variations related to drought tolerance in wheat (Triticum aestivum L.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:37. [PMID: 36897407 DOI: 10.1007/s00122-023-04283-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 11/07/2022] [Indexed: 06/18/2023]
Abstract
Structural variations are common in plant genomes, affecting meiotic recombination and distorted segregation in wheat. And presence/absence variations can significantly affect drought tolerance in wheat. Drought is a major abiotic stress limiting wheat production. Common wheat has a complex genome with three sub-genomes, which host large numbers of structural variations (SVs). SVs play critical roles in understanding the genetic contributions of plant domestication and phenotypic plasticity, but little is known about their genomic characteristics and their effects on drought tolerance. In the present study, high-resolution karyotypes of 180 doubled haploids (DHs) were developed. Signal polymorphisms between the parents involved with 8 presence-absence variations (PAVs) of tandem repeats (TR) distributed on the 7 (2A, 4A, 5A, 7A, 3B, 7B, and 2D) of 21 chromosomes. Among them, PAV on chromosome 2D showed distorted segregation, others transmit normal conforming to a 1:1 segregation ration in the population; and a PAVs recombination occurred on chromosome 2A. Association analysis of PAV and phenotypic traits under different water regimes, we found PAVs on chromosomes 4A, 5A, and 7B showed negative effect on grain length (GL) and grain width (GW); PAV.7A had opposite effect on grain thickness (GT) and spike length (SL), with the effect on traits differing under different water regimes. PAVs on linkage group 2A, 4A, 7A, 2D, and 7B associated with the drought tolerance coefficients (DTCs), and significant negative effect on drought resistance values (D values) were detected in PAV.7B. Additionally, quantitative trait loci (QTL) associated with phenotypic traits using the 90 K SNP array showed QTL for DTCs and grain-related traits in chromosomes 4A, and 5A, 3B were co-localized in differential regions of PAVs. These PAVs can cause the differentiation of the target region of SNP and could be used for genetic improvement of agronomic traits under drought stress via marker-assisted selection (MAS) breeding.
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Affiliation(s)
- Jiajia Zhao
- College of Agriculture, State Key Laboratory of Sustainable Dryland Agriculture, Shanxi Agricultural University, Taigu, China
- Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Xiaohua Li
- Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
| | - Ling Qiao
- Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
| | - Xingwei Zheng
- Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
| | - Bangbang Wu
- Institute of Wheat Research, Shanxi Agricultural University, Linfen, China
| | - Meijun Guo
- College of Agriculture, State Key Laboratory of Sustainable Dryland Agriculture, Shanxi Agricultural University, Taigu, China
- Jinzhong University, Jinzhong, China
| | - Meichen Feng
- College of Agriculture, State Key Laboratory of Sustainable Dryland Agriculture, Shanxi Agricultural University, Taigu, China
| | - Zengjun Qi
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, China
| | - Wude Yang
- College of Agriculture, State Key Laboratory of Sustainable Dryland Agriculture, Shanxi Agricultural University, Taigu, China.
| | - Jun Zheng
- Institute of Wheat Research, Shanxi Agricultural University, Linfen, China.
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Yu H, Zhang L, He X, Zhang T, Wang C, Lu J, He X, Chen K, Gu W, Cheng S, Hu Y, Yao B, Jian A, Yu X, Zheng H, You S, Wang Q, Lei D, Jiang L, Zhao Z, Wan J. OsPHS1 is required for both male and female gamete development in rice. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 325:111480. [PMID: 36183810 DOI: 10.1016/j.plantsci.2022.111480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 09/13/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Meiosis plays an essential role in the production of male and female gametes. Extensive studies have elucidated that homologous chromosome association and pairing are essential for crossing-over and recombination of chromosomal segments. However, the molecular mechanism of chromosome recognition and pairing remains elusive. Here, we identified a rice male-female sterility mutant plant. Cytological observations showed that the development of both pollen and embryo sacs of the mutant were abnormal due to defects in homologous chromosome recognition and pairing during prophase I. Map-based cloning revealed that Os06g0473000 encoding a poor homologous synapsis 1 (PHS1) protein is the candidate target gene, which was confirmed by knockout using CRISPR/Cas9 technology. Sequence analysis revealed a single base mutation (G > A) involving the junction of the fourth exon and intron of OsPHS1, which is predicted to alter splicing, resulting in an Osphs1 mutant. Expression pattern analysis indicated that OsPHS1 expression levels were mainly expressed in panicles at the beginning of meiosis. Subcellular localization analysis demonstrated that the OsPHS1 protein is situated in the nucleus and cytoplasm. Taken together, our results suggest an important role for OsPHS1 in homologous chromosome pairing in both male and female gametogenesis in rice.
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Affiliation(s)
- Hao Yu
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Liping Zhang
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaojuan He
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Taohui Zhang
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Chaolong Wang
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Jiayu Lu
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaodong He
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Keyi Chen
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Weihang Gu
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Siqi Cheng
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Yang Hu
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Bowen Yao
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Anqi Jian
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaowen Yu
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Hai Zheng
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Shimin You
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Qiming Wang
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Dekun Lei
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Ling Jiang
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhigang Zhao
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China.
| | - Jianmin Wan
- National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center, Nanjing Agricultural University, Nanjing 210095, China; National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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5
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Garcia N, Yin L, Dukowic-Schulze S, Milsted C, Kianian PMA, Kianian S, Pawlowski WP, Chen C. Comparison of meiotic transcriptomes of three maize inbreds with different origins reveals differences in cell cycle and recombination. BMC Genomics 2022; 23:702. [PMID: 36224518 PMCID: PMC9554999 DOI: 10.1186/s12864-022-08922-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/28/2022] [Indexed: 11/21/2022] Open
Abstract
Background Cellular events during meiosis can differ between inbred lines in maize. Substantial differences in the average numbers of chiasmata and double-strand breaks (DSBs) per meiotic cell have been documented among diverse inbred lines of maize: CML228, a tropical maize inbred line, B73 and Mo17, temperate maize lines. To determine if gene expression might explain these observed differences, an RNA-Seq experiment was performed on CML228 male meiocytes which was compared to B73 and Mo17 male meiocytes, where plants were grown in the same controlled environment. Results We found that a few DSB-repair/meiotic genes which promote class I crossovers (COs) and the Zyp1 gene which limits newly formed class I COs were up-regulated, whereas Mus81 homolog 2 which promotes class II COs was down-regulated in CML228. Although we did not find enriched gene ontology (GO) categories directly related to meiosis, we found that GO categories in membrane, localization, proteolysis, energy processes were up-regulated in CML228, while chromatin remodeling, epigenetic regulation, and cell cycle related processes including meiosis related cell cycle processes were down-regulated in CML228. The degree of similarity in expression patterns between the three maize lines reflect their genetic relatedness: B73 and Mo17 had similar meiotic expressions and CML228 had a more distinct expression profile. Conclusions We found that meiotic related genes were mostly conserved among the three maize inbreds except for a few DSB-repair/meiotic genes. The findings that the molecular players in limiting class I CO formation (once CO assurance is achieved) were up-regulated and those involved in promoting class II CO formation were down-regulated in CML228 agree with the lower chiasmata number observed in CML228 previously. In addition, epigenetics such as chromatin remodeling and histone modification might play a role. Transport and energy-related processes was up-regulated and Cyclin13 was down-regulated in CML228. The direction of gene expression of these processes agree with that previously found in meiotic tissues compared with vegetative tissues. In summary, we used different natural maize inbred lines from different climatic conditions and have shown their differences in expression landscape in male meiocytes. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08922-w.
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Affiliation(s)
- Nelson Garcia
- Department of Horticultural Science, University of Minnesota, Saint Paul, MN, USA.,Present Address: Sound Agriculture, 5858 Horton St, Emeryville, CA, USA
| | - Lu Yin
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Stefanie Dukowic-Schulze
- Department of Horticultural Science, University of Minnesota, Saint Paul, MN, USA.,Microvascular Biology and Pathobiology, University of Heidelberg, Mannheim, Germany
| | - Claire Milsted
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Penny M A Kianian
- PepsiCo Inc., 210 Borlaug Hall, 1991 Upper Buford Circle, Saint Paul, MN, USA
| | - Shahryar Kianian
- Department of Agriculture - Agricultural Research Service, Cereal Disease Lab, U.S., Saint Paul, MN, USA
| | | | - Changbin Chen
- Department of Horticultural Science, University of Minnesota, Saint Paul, MN, USA. .,School of Life Sciences, Arizona State University, Tempe, AZ, USA.
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Li Y, Huang Y, Sun H, Wang T, Ru W, Pan L, Zhao X, Dong Z, Huang W, Jin W. Heat shock protein 101 contributes to the thermotolerance of male meiosis in maize. THE PLANT CELL 2022; 34:3702-3717. [PMID: 35758611 PMCID: PMC9516056 DOI: 10.1093/plcell/koac184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 06/17/2022] [Indexed: 05/12/2023]
Abstract
High temperatures interfere with meiotic recombination and the subsequent progression of meiosis in plants, but few genes involved in meiotic thermotolerance have been characterized. Here, we characterize a maize (Zea mays) classic dominant male-sterile mutant Ms42, which has defects in pairing and synapsis of homologous chromosomes and DNA double-strand break (DSB) repair. Ms42 encodes a member of the heat shock protein family, HSP101, which accumulates in pollen mother cells. Analysis of the dominant Ms42 mutant and hsp101 null mutants reveals that HSP101 functions in RADIATION SENSITIVE 51 loading, DSB repair, and subsequent meiosis. Consistent with these functions, overexpression of Hsp101 in anthers results in robust microspores with enhanced heat tolerance. These results demonstrate that HSP101 mediates thermotolerance during microsporogenesis, shedding light on the genetic basis underlying the adaptation of male meiocytes to high temperatures.
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Affiliation(s)
- Yunfei Li
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, Key Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University, Beijing 100193, China
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Yumin Huang
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, Key Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University, Beijing 100193, China
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Huayue Sun
- College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Tianyi Wang
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, Key Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University, Beijing 100193, China
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Wei Ru
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, Key Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University, Beijing 100193, China
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Lingling Pan
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, Key Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University, Beijing 100193, China
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Xiaoming Zhao
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Zhaobin Dong
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, Key Laboratory of Crop Heterosis and Utilization, Ministry of Education, China Agricultural University, Beijing 100193, China
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing 100193, China
| | - Wei Huang
- Author for correspondence: (W.H.), (W.J.)
| | - Weiwei Jin
- Author for correspondence: (W.H.), (W.J.)
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Continuous double-strand break induction and their differential processing sustain chiasma formation during Caenorhabditis elegans meiosis. Cell Rep 2022; 40:111403. [PMID: 36170820 DOI: 10.1016/j.celrep.2022.111403] [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: 01/10/2022] [Revised: 06/01/2022] [Accepted: 09/01/2022] [Indexed: 11/22/2022] Open
Abstract
Faithful chromosome segregation into gametes depends on Spo11-induced DNA double-strand breaks (DSBs). These yield single-stranded 3' tails upon resection to promote crossovers (COs). While early Mre11-dependent end resection is the predominant pathway in most organisms, Exo1 or Dna2/BLM can also contribute to the efficient processing of meiotic DSBs. Although its enzymatic activity has been thoroughly dissected, the temporal dynamics underlying Spo11 activity have remained mostly elusive. We show that, in Caenorhabditis elegans, SPO-11-mediated DSB induction takes place throughout early meiotic prophase I until mid-late pachynema. We find that late DSBs are essential for CO formation and are preferentially processed by EXO-1 and DNA-2 in a redundant fashion. Further, EXO-1-DNA-2-mediated resection ensures completion of conservative DSB repair and discourages activation of KU-dependent end joining. Taken together, our data unveil important temporal aspects of DSB induction and identify previously unknown functional implications for EXO-1-DNA-2-mediated resection activity in C. elegans.
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8
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Wang Y, Wang Y, Zang J, Chen H, He Y. ZmPRD1 is essential for double-strand break formation, but is not required for bipolar spindle assembly during maize meiosis. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3386-3400. [PMID: 35201286 DOI: 10.1093/jxb/erac075] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 02/23/2022] [Indexed: 06/14/2023]
Abstract
Homologs of PUTATIVE RECOMBINATION INITIATION DEFECT 1 (PRD1) are known to be essential for meiotic double-strand break (DSB) formation in mouse (Mus musculus), Arabidopsis, and rice (Oryza sativa). Recent research has shown that rice PRD1 also plays an unanticipated role in meiotic bipolar spindle assembly, revealing that PRD1 has multiple functions in plant meiosis. In this study, we characterize the meiotic function of PRD1 in maize (Zea mays; ZmPRD1). Our results show that Zmprd1 mutant plants display normal vegetative growth but have complete male and female sterility. Meiotic DSB formation is fully abolished in mutant meiocytes, leading to failure in homologous pairing, synapsis, and recombination. ZmPRD1 exhibits a different pattern of chromosome localization compared to its rice homologs. The ZmPRD1 protein interacts with several DSB-forming proteins, but does not directly interact with the kinetochore proteins REC8 and SGO1. Possibly as a result of this, there are no significant abnormalities of bipolar spindle assembly in Zmprd1 meiocytes. Overall, our results demonstrate that ZmPRD1 is essential for DSB formation and homologous recombination in maize meiosis. However, the recently-identified function of PRD1 in bipolar spindle assembly during rice meiosis is not conserved in maize.
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Affiliation(s)
- Yazhong Wang
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, China
| | - Yan Wang
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, China
| | - Jie Zang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Huabang Chen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yan He
- MOE Key Laboratory of Crop Heterosis and Utilization, National Maize Improvement Center of China, China Agricultural University, Beijing, China
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9
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Yang F, Pecinka A. Multiple Roles of SMC5/6 Complex during Plant Sexual Reproduction. Int J Mol Sci 2022; 23:ijms23094503. [PMID: 35562893 PMCID: PMC9099584 DOI: 10.3390/ijms23094503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/06/2022] [Accepted: 04/13/2022] [Indexed: 12/01/2022] Open
Abstract
Chromatin-based processes are essential for cellular functions. Structural maintenance of chromosomes (SMCs) are evolutionarily conserved molecular machines that organize chromosomes throughout the cell cycle, mediate chromosome compaction, promote DNA repair, or control sister chromatid attachment. The SMC5/6 complex is known for its pivotal role during the maintenance of genome stability. However, a dozen recent plant studies expanded the repertoire of SMC5/6 complex functions to the entire plant sexual reproductive phase. The SMC5/6 complex is essential in meiosis, where its activity must be precisely regulated to allow for normal meiocyte development. Initially, it is attenuated by the recombinase RAD51 to allow for efficient strand invasion by the meiosis-specific recombinase DMC1. At later stages, it is essential for the normal ratio of interfering and non-interfering crossovers, detoxifying aberrant joint molecules, preventing chromosome fragmentation, and ensuring normal chromosome/sister chromatid segregation. The latter meiotic defects lead to the production of diploid male gametes in Arabidopsis SMC5/6 complex mutants, increased seed abortion, and production of triploid offspring. The SMC5/6 complex is directly involved in controlling normal embryo and endosperm cell divisions, and pioneer studies show that the SMC5/6 complex is also important for seed development and normal plant growth in cereals.
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Affiliation(s)
- Fen Yang
- Centre of the Region Haná for Biotechnological and Agricultural Research (CRH), Institute of Experimental Botany (IEB), Czech Academy of Sciences, 77900 Olomouc, Czech Republic;
- Department of Cell Biology and Genetics, Faculty of Science, Palacký University, 77900 Olomouc, Czech Republic
| | - Ales Pecinka
- Centre of the Region Haná for Biotechnological and Agricultural Research (CRH), Institute of Experimental Botany (IEB), Czech Academy of Sciences, 77900 Olomouc, Czech Republic;
- Department of Cell Biology and Genetics, Faculty of Science, Palacký University, 77900 Olomouc, Czech Republic
- Correspondence:
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10
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Rousova D, Nivsarkar V, Altmannova V, Raina VB, Funk SK, Liedtke D, Janning P, Müller F, Reichle H, Vader G, Weir JR. Novel mechanistic insights into the role of Mer2 as the keystone of meiotic DNA break formation. eLife 2021; 10:72330. [PMID: 34951404 PMCID: PMC8848140 DOI: 10.7554/elife.72330] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 12/23/2021] [Indexed: 12/05/2022] Open
Abstract
In meiosis, DNA double-strand break (DSB) formation by Spo11 initiates recombination and enables chromosome segregation. Numerous factors are required for Spo11 activity, and couple the DSB machinery to the development of a meiosis-specific ‘axis-tethered loop’ chromosome organisation. Through in vitro reconstitution and budding yeast genetics, we here provide architectural insight into the DSB machinery by focussing on a foundational DSB factor, Mer2. We characterise the interaction of Mer2 with the histone reader Spp1, and show that Mer2 directly associates with nucleosomes, likely highlighting a contribution of Mer2 to tethering DSB factors to chromatin. We reveal the biochemical basis of Mer2 association with Hop1, a HORMA domain-containing chromosomal axis factor. Finally, we identify a conserved region within Mer2 crucial for DSB activity, and show that this region of Mer2 interacts with the DSB factor Mre11. In combination with previous work, we establish Mer2 as a keystone of the DSB machinery by bridging key protein complexes involved in the initiation of meiotic recombination. Organisms are said to be diploid when they carry two copies of each chromosome in their cells, one from each of their biological parents. But in order for each parent to only pass on one copy of their own chromosomes, they need to make haploid cells, which only carry one copy of each chromosome. These cells form by a special kind of cell division called meiosis, in which the two chromosomes from each pair in the parent cells are first linked, and then pulled apart into the daughter cells. Accurate meiosis requires a type of DNA damage called double-stranded DNA breaks. These breaks cut through the chromosomes and can be dangerous to the cell if they are not repaired correctly. During meiosis, a set of proteins gather around the chromosomes to ensure the cuts happen in the right place and to repair the damage. One of these proteins is called Mer2. Previous studies suggest that this protein plays a role in placing the DNA breaks and controlling when they happen. To find out more, Rousova et al. examined Mer2 and the proteins that interact with it in budding yeast cells. This involved taking the proteins out of the cell to get a closer look. The experiments showed that Mer2 sticks directly to the chromosomes and acts as a tether for other proteins. It collaborates with two partners, called Hop1 and Mre11, to make sure that DNA breaks happen safely. These proteins detect the state of the chromosome and repair the damage. Stopping Mer2 from interacting with Mre11 prevented DNA breaks from forming in budding yeast cells. Although Rousova et al. used budding yeast to study the proteins involved in meiosis, similar proteins exist in plant and animal cells too. Understanding how they work could open new avenues of research into cell division. For example, studies on plant proteins could provide tools for creating new crop strains. Studies on human proteins could also provide insights into fertility problems and cancer.
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Affiliation(s)
| | - Vaishnavi Nivsarkar
- Department of Mechanistic Cell Biology, Max Planck Institute for Molecular Physiology, Dortmund, Germany
| | | | - Vivek B Raina
- Department of Mechanistic Cell Biology, Max Planck Institute for Molecular Physiology, Dortmund, Germany
| | | | | | - Petra Janning
- Department of Mechanistic Cell Biology, Max Planck Institute for Molecular Physiology, Dortmund, Germany
| | - Franziska Müller
- Department of Mechanistic Cell Biology, Max Planck Institute for Molecular Physiology, Dortmund, Germany
| | | | - Gerben Vader
- Department of Human Genetics, Cancer Centre Amsterdam, Amsterdam, Netherlands
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11
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RNA-DNA hybrids regulate meiotic recombination. Cell Rep 2021; 37:110097. [PMID: 34879269 DOI: 10.1016/j.celrep.2021.110097] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 07/26/2021] [Accepted: 11/14/2021] [Indexed: 01/07/2023] Open
Abstract
RNA-DNA hybrids are often associated with genome instability and also function as a cellular regulator in many biological processes. In this study, we show that accumulated RNA-DNA hybrids cause multiple defects in budding yeast meiosis, including decreased sporulation efficiency and spore viability. Further analysis shows that these RNA-DNA hybrid foci colocalize with RPA/Rad51 foci on chromosomes. The efficient formation of RNA-DNA hybrid foci depends on Rad52 and ssDNA ends of meiotic DNA double-strand breaks (DSBs), and their number is correlated with DSB frequency. Interestingly, RNA-DNA hybrid foci and recombination foci show similar dynamics. The excessive accumulation of RNA-DNA hybrids around DSBs competes with Rad51/Dmc1, impairs homolog bias, and decreases crossover and noncrossover recombination. Furthermore, precocious removal of RNA-DNA hybrids by RNase H1 overexpression also impairs meiotic recombination similarly. Taken together, our results demonstrate that RNA-DNA hybrids form at ssDNA ends of DSBs to actively regulate meiotic recombination.
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12
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Atkins A, Chung CH, Allen AG, Dampier W, Gurrola TE, Sariyer IK, Nonnemacher MR, Wigdahl B. Off-Target Analysis in Gene Editing and Applications for Clinical Translation of CRISPR/Cas9 in HIV-1 Therapy. Front Genome Ed 2021; 3:673022. [PMID: 34713260 PMCID: PMC8525399 DOI: 10.3389/fgeed.2021.673022] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 06/21/2021] [Indexed: 12/26/2022] Open
Abstract
As genome-editing nucleases move toward broader clinical applications, the need to define the limits of their specificity and efficiency increases. A variety of approaches for nuclease cleavage detection have been developed, allowing a full-genome survey of the targeting landscape and the detection of a variety of repair outcomes for nuclease-induced double-strand breaks. Each approach has advantages and disadvantages relating to the means of target-site capture, target enrichment mechanism, cellular environment, false discovery, and validation of bona fide off-target cleavage sites in cells. This review examines the strengths, limitations, and origins of the different classes of off-target cleavage detection systems including anchored primer enrichment (GUIDE-seq), in situ detection (BLISS), in vitro selection libraries (CIRCLE-seq), chromatin immunoprecipitation (ChIP) (DISCOVER-Seq), translocation sequencing (LAM PCR HTGTS), and in vitro genomic DNA digestion (Digenome-seq and SITE-Seq). Emphasis is placed on the specific modifications that give rise to the enhanced performance of contemporary techniques over their predecessors and the comparative performance of techniques for different applications. The clinical relevance of these techniques is discussed in the context of assessing the safety of novel CRISPR/Cas9 HIV-1 curative strategies. With the recent success of HIV-1 and SIV-1 viral suppression in humanized mice and non-human primates, respectively, using CRISPR/Cas9, rigorous exploration of potential off-target effects is of critical importance. Such analyses would benefit from the application of the techniques discussed in this review.
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Affiliation(s)
- Andrew Atkins
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Cheng-Han Chung
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Alexander G. Allen
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Will Dampier
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Theodore E. Gurrola
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Ilker K. Sariyer
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, Philadelphia, PA, United States
| | - Michael R. Nonnemacher
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Brian Wigdahl
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States,Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States,Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, United States,*Correspondence: Brian Wigdahl
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13
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Gartner A, Engebrecht J. DNA repair, recombination, and damage signaling. Genetics 2021; 220:6522877. [PMID: 35137093 PMCID: PMC9097270 DOI: 10.1093/genetics/iyab178] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/10/2021] [Indexed: 01/09/2023] Open
Abstract
DNA must be accurately copied and propagated from one cell division to the next, and from one generation to the next. To ensure the faithful transmission of the genome, a plethora of distinct as well as overlapping DNA repair and recombination pathways have evolved. These pathways repair a large variety of lesions, including alterations to single nucleotides and DNA single and double-strand breaks, that are generated as a consequence of normal cellular function or by external DNA damaging agents. In addition to the proteins that mediate DNA repair, checkpoint pathways have also evolved to monitor the genome and coordinate the action of various repair pathways. Checkpoints facilitate repair by mediating a transient cell cycle arrest, or through initiation of cell suicide if DNA damage has overwhelmed repair capacity. In this chapter, we describe the attributes of Caenorhabditis elegans that facilitate analyses of DNA repair, recombination, and checkpoint signaling in the context of a whole animal. We review the current knowledge of C. elegans DNA repair, recombination, and DNA damage response pathways, and their role during development, growth, and in the germ line. We also discuss how the analysis of mutational signatures in C. elegans is helping to inform cancer mutational signatures in humans.
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Affiliation(s)
- Anton Gartner
- Department for Biological Sciences, IBS Center for Genomic Integrity, Ulsan National Institute of Science and Technology, Ulsan 689-798, Republic of Korea,Corresponding author: (A.G.); (J.E.)
| | - JoAnne Engebrecht
- Department of Molecular and Cellular Biology, University of California Davis, Davis, CA 95616, USA,Corresponding author: (A.G.); (J.E.)
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14
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MRE11 Is Crucial for Malaria Parasite Transmission and Its Absence Affects Expression of Interconnected Networks of Key Genes Essential for Life. Cells 2020; 9:cells9122590. [PMID: 33287434 PMCID: PMC7761864 DOI: 10.3390/cells9122590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 11/16/2022] Open
Abstract
The meiotic recombination 11 protein (MRE11) plays a key role in DNA damage response and maintenance of genome stability. However, little is known about its function during development of the malaria parasite Plasmodium. Here, we present a functional, ultrastructural and transcriptomic analysis of Plasmodium parasites lacking MRE11 during its life cycle in both mammalian and mosquito vector hosts. Genetic disruption of Plasmodium berghei mre11 (PbMRE11) results in significant retardation of oocyst development in the mosquito midgut associated with cytoplasmic and nuclear degeneration, along with concomitant ablation of sporogony and subsequent parasite transmission. Further, absence of PbMRE11 results in significant transcriptional downregulation of genes involved in key interconnected biological processes that are fundamental to all eukaryotic life including ribonucleoprotein biogenesis, spliceosome function and iron-sulfur cluster assembly. Overall, our study provides a comprehensive functional analysis of MRE11's role in Plasmodium development during the mosquito stages and offers a potential target for therapeutic intervention during malaria parasite transmission.
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15
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Correll-Tash S, Lilley B, Salmons Iv H, Mlynarski E, Franconi CP, McNamara M, Woodbury C, Easley CA, Emanuel BS. Double strand breaks (DSBs) as indicators of genomic instability in PATRR-mediated translocations. Hum Mol Genet 2020; 29:3872-3881. [PMID: 33258468 DOI: 10.1093/hmg/ddaa251] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 10/05/2020] [Accepted: 11/25/2020] [Indexed: 02/06/2023] Open
Abstract
Genomic instability contributes to a variety of potentially damaging conditions, including DNA-based rearrangements. Breakage in the form of double strand breaks (DSBs) increases the likelihood of DNA damage, mutations and translocations. Certain human DNA regions are known to be involved in recurrent translocations, such as the palindrome-mediated rearrangements that have been identified at the breakpoints of several recurrent constitutional translocations: t(11;22)(q23;q11), t(17;22)(q11;q11) and t(8;22) (q24;q11). These breakpoints occur at the center of palindromic AT-rich repeats (PATRRs), which suggests that the structure of the DNA may play a contributory role, potentially through the formation of secondary cruciform structures. The current study analyzed the DSB propensity of these PATRR regions in both lymphoblastoid (mitotic) and spermatogenic cells (meiotic). Initial results found an increased association of sister chromatid exchanges (SCEs) at PATRR regions in experiments that used SCEs to assay DSBs, combining SCE staining with fluorescence in situ hybridization (FISH). Additional experiments used chromatin immunoprecipitation (ChIP) with antibodies for either markers of DSBs or proteins involved in DSB repair along with quantitative polymerase chain reaction to quantify the frequency of DSBs occurring at PATRR regions. The results indicate an increased rate of DSBs at PATRR regions. Additional ChIP experiments with the cruciform binding 2D3 antibody indicate an increased rate of cruciform structures at PATRR regions in both mitotic and meiotic samples. Overall, these experiments demonstrate an elevated rate of DSBs at PATRR regions, an indication that the structure of PATRR containing DNA may lead to increased breakage in multiple cellular environments.
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Affiliation(s)
- Sarah Correll-Tash
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Brenna Lilley
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Harold Salmons Iv
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Elisabeth Mlynarski
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Colleen P Franconi
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Meghan McNamara
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Carson Woodbury
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Charles A Easley
- Department of Environmental Health Sciences, College of Public Health at the University of Georgia, Athens, GA, 30602, USA
| | - Beverly S Emanuel
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Department of Pediatrics, Perelman School of Medicine of the University of Pennsylvania, Philadelphia, PA 19104, USA
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16
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Gaurav S, Ranjan R, Kuldeep J, Dhiman K, Mahapatra PP, Ashish, Siddiqi MI, Ahmed S. The N-terminus region of Drp1, a Rint1 family protein is essential for cell survival and its interaction with Rad50 protein in fission yeast S.pombe. Biochim Biophys Acta Gen Subj 2020; 1865:129739. [PMID: 32956753 DOI: 10.1016/j.bbagen.2020.129739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Defects in DNA repair pathway can lead to double-strand breaks leading to genomic instability. Earlier we have shown that S.pombe Drp1, a Rint1/Tip1 family protein is required for the recovery from DNA damage. METHODS Various truncations of Drp1 protein were constructed and their role in DNA damage response and interaction with Rad50 protein has been studied by co-immunoprecipitation and pull-down assays. RESULTS The structural and functional analysis of Drp1 protein revealed that the N-terminus region of Drp1 is indispensable for the survival. The C-terminus truncation mutants, drp1C1Δ and drp1C2Δ exhibit temperature sensitive phenotype and are hypersensitive against DNA damaging agents with elevated level of Rad52-YFP foci at non-permissive temperature indicating the impairment for DNA damage repair pathway. The essential N-terminus region of Drp1 interacts with the C-terminus region of Rad50 and might be involved in influencing the MRN/X function. Small-angle X-ray (SAXS) analysis revealed three-domain like shapes in Drp1 protein while the C-terminus region of Rad50 exhibit unusual bulges. Computational docking studies revealed the amino acid residues at the C-terminus region of Rad50 that are involved in the interaction with the residues present at the N-terminal region of Drp1 indicating the importance of the N-terminal region of Drp1 protein. CONCLUSIONS We have identified the region of Drp1 and Rad50 proteins that are involved in the interaction and their role in the DNA damage response pathway has been analyzed. GENERAL SIGNIFICANCE The functional and structural aspects of fission yeast Drp1 protein and its interaction with Rad50 have been elucidated.
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Affiliation(s)
- Sachin Gaurav
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Rajeev Ranjan
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Jitendra Kuldeep
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Kanika Dhiman
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Pinaki Prasad Mahapatra
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Ashish
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Mohammad Imran Siddiqi
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
| | - Shakil Ahmed
- Molecular and Structural Biology Division, CSIR- Central Drug Research Institute, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India.
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17
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Wang H, Cao Q, Zhao Q, Arfan M, Liu W. Mechanisms used by DNA MMR system to cope with Cadmium-induced DNA damage in plants. CHEMOSPHERE 2020; 246:125614. [PMID: 31883478 DOI: 10.1016/j.chemosphere.2019.125614] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 12/07/2019] [Accepted: 12/09/2019] [Indexed: 05/27/2023]
Abstract
Cadmium (Cd) is found widely in soil and is severely toxic for plants, causing oxidative damage in plant cells because of its heavy metal characteristics. The DNA damage response (DDR) is triggered in plants to cope with the Cd stress. The DNA mismatch repair (MMR) system known for its mismatch repair function determines DDR, as mispairs are easily generated by a translesional synthesis under Cd-induced genomic instability. Cd-induced mismatches are recognized by three heterodimeric complexes including MutSα (MSH2/MSH6), MutSβ (MSH2/MSH3), and MutSγ (MSH2/MSH7). MutLα (MLH1/PMS1), PCNA/RFC, EXO1, DNA polymerase δ and DNA ligase participate in mismatch repair in turn. Meanwhile, ATR is preferentially activated by MSH2 to trigger DDR including the regulation of the cell cycle, endoreduplication, cell death, and recruitment of other DNA repair, which enhances plant tolerance to Cd. However, plants with deficient MutS will bypass MMR-mediated DDR and release the multiple-effect MLH1 from requisition of the MMR system, which leads to weak tolerance to Cd in plants. In this review, we systematically illustrate how the plant DNA MMR system works in a Cd-induced DDR, and how MMR genes regulate plant tolerance to Cd. Additionally, we also reviewed multiple epigenetic regulation systems acting on MMR genes under stress.
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Affiliation(s)
- Hetong Wang
- Liaoning Key Laboratory of Urban Integrated Pest Management and Ecological Security, College of Life Science and Bioengineering, Shenyang University, Shenyang, 110044, PR China.
| | - Qijiang Cao
- Liaoning Key Laboratory of Urban Integrated Pest Management and Ecological Security, College of Life Science and Bioengineering, Shenyang University, Shenyang, 110044, PR China.
| | - Qiang Zhao
- Agricultural College, Shenyang Agricultural University, Shenyang, 110866, PR China.
| | - Muhammad Arfan
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, PR China.
| | - Wan Liu
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, 110016, PR China.
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18
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Hu M, Li L, Liu S, Lou Y, Wang L, Le F, Li H, Wang Q, Lou H, Wang N, Jin F. Decreased expression of MRE11 and RAD50 in testes from humans with spermatogenic failure. J Assist Reprod Genet 2020; 37:331-340. [PMID: 31983050 PMCID: PMC7056783 DOI: 10.1007/s10815-019-01686-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 12/27/2019] [Indexed: 12/31/2022] Open
Abstract
PURPOSE To assess testicular mRNA and protein expression levels of MRE11 and RAD50 in human azoospermia patients. METHODS Patients diagnosed with maturation arrest at the spermatocyte stage (MA) and Sertoli cell-only syndrome (SCOS) were recruited through diagnostic testicular biopsy. Patients with normal spermatogenesis were studied as controls. In addition, knockdown of MRE11 and RAD50 was performed in GC-2spd(ts) cells to investigate their roles in cellular proliferation and apoptosis. RESULTS mRNA and protein expression levels of MRE11 and RAD50 were measured using quantitative polymerase chain reaction, western blotting, and immunohistochemistry, respectively. Knockdown of both MRE11 and RAD50 utilized transfection with small interfering RNAs. CONCLUSION Our findings demonstrated altered expression levels of MRE11 and RAD50 in human testes with MA and SCOS, and showed that these alterations might be associated with impaired spermatogenesis. These results offer valuable new perspectives into the molecular mechanisms of male infertility.
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Affiliation(s)
- Minhao Hu
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, 1 Xueshi Road, Hangzhou, 310006, Zhejiang, China
| | - Lejun Li
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, 1 Xueshi Road, Hangzhou, 310006, Zhejiang, China
| | - Shuyuan Liu
- Department of Gynecology, Weifang Maternal and Child Health Hospital, Weifang, 261000, China
| | - Yiyun Lou
- Department of Gynecology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou, 310007, China
| | - Liya Wang
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, 1 Xueshi Road, Hangzhou, 310006, Zhejiang, China
| | - Fang Le
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, 1 Xueshi Road, Hangzhou, 310006, Zhejiang, China
| | - Hongping Li
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, 1 Xueshi Road, Hangzhou, 310006, Zhejiang, China
| | - Qijing Wang
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, 1 Xueshi Road, Hangzhou, 310006, Zhejiang, China
| | - Hangying Lou
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, 1 Xueshi Road, Hangzhou, 310006, Zhejiang, China
| | - Ning Wang
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, 1 Xueshi Road, Hangzhou, 310006, Zhejiang, China
| | - Fan Jin
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, 1 Xueshi Road, Hangzhou, 310006, Zhejiang, China.
- Women's Reproductive Health Laboratory of Zhejiang Province, Key Laboratory of Reproductive Genetics, Ministry of Education, Hangzhou, 310006, China.
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19
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Zhang C, Ren X, Wang X, Wan Q, Ding K, Chen L. FgRad50 Regulates Fungal Development, Pathogenicity, Cell Wall Integrity and the DNA Damage Response in Fusarium graminearum. Front Microbiol 2020; 10:2970. [PMID: 31998262 PMCID: PMC6962240 DOI: 10.3389/fmicb.2019.02970] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 12/09/2019] [Indexed: 12/26/2022] Open
Abstract
Rad50 is a member of the double strand break repair epistasis group of proteins that play important roles in regulating DNA damage checkpoint signaling, telomere maintenance, homologous recombination and non-homologous end-joining in eukaryotes. However, the function of Rad50 in fungal plant pathogens remains unknown. In this study, we report the functional investigation of FgRad50 in the wheat head blight pathogen Fusarium graminearum. FgRad50 is an ortholog of Saccharomyces cerevisiae Rad50 that could restore the sensitivity of the yeast Rad50 mutant to DNA damage agents. The FgRad50 deletion mutant (ΔFgRad50) exhibited defective vegetative growth, asexual/sexual development and virulence, as well as disrupted deoxynivalenol biosynthesis. Moreover, deletion of FgRad50 resulted in hypersensitivity to DNA damage agents. Unexpectedly, FgRad50 plays a key role in responses to cell wall-damaging agents by negatively regulating phosphorylation of FgMgv1, a MAP kinase in the cell wall integrity (CWI) pathway. Taken together, these results suggest that FgRad50 plays critical roles in fungal development, virulence and secondary metabolism in F. graminearum, as well as CWI and the DNA damage response.
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Affiliation(s)
- Chengqi Zhang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, College of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Xuexiang Ren
- Institute of Plant Protection and Agro-Products Safety, Anhui Academy of Agricultural Sciences, Hefei, China
| | - Xintong Wang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, College of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Qiong Wan
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, College of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Kejian Ding
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, College of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Li Chen
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, College of Plant Protection, Anhui Agricultural University, Hefei, China
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Oh J, Symington LS. Role of the Mre11 Complex in Preserving Genome Integrity. Genes (Basel) 2018; 9:E589. [PMID: 30501098 PMCID: PMC6315862 DOI: 10.3390/genes9120589] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 11/26/2018] [Accepted: 11/27/2018] [Indexed: 12/12/2022] Open
Abstract
DNA double-strand breaks (DSBs) are hazardous lesions that threaten genome integrity and cell survival. The DNA damage response (DDR) safeguards the genome by sensing DSBs, halting cell cycle progression and promoting repair through either non-homologous end joining (NHEJ) or homologous recombination (HR). The Mre11-Rad50-Xrs2/Nbs1 (MRX/N) complex is central to the DDR through its structural, enzymatic, and signaling roles. The complex tethers DNA ends, activates the Tel1/ATM kinase, resolves protein-bound or hairpin-capped DNA ends, and maintains telomere homeostasis. In addition to its role at DSBs, MRX/N associates with unperturbed replication forks, as well as stalled replication forks, to ensure complete DNA synthesis and to prevent chromosome rearrangements. Here, we summarize the significant progress made in characterizing the MRX/N complex and its various activities in chromosome metabolism.
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Affiliation(s)
- Julyun Oh
- Biological Sciences Program, Columbia University, New York, NY 10027, USA.
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA.
| | - Lorraine S Symington
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA.
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21
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Oh J, Lee SJ, Rothstein R, Symington LS. Xrs2 and Tel1 Independently Contribute to MR-Mediated DNA Tethering and Replisome Stability. Cell Rep 2018; 25:1681-1692.e4. [PMID: 30428339 PMCID: PMC6317890 DOI: 10.1016/j.celrep.2018.10.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 09/08/2018] [Accepted: 10/05/2018] [Indexed: 02/04/2023] Open
Abstract
The yeast Mre11-Rad50-Xrs2 (MRX) complex has structural, signaling, and catalytic functions in the response to DNA damage. Xrs2, the eukaryotic-specific component of the complex, is required for nuclear import of Mre11 and Rad50 and to recruit the Tel1 kinase to damage sites. We show that nuclear-localized MR complex (Mre11-NLS) catalyzes homology-dependent repair without Xrs2, but MR cannot activate Tel1, and it fails to tether DSBs, resulting in sensitivity to genotoxins, replisome instability, and increased gross chromosome rearrangements (GCRs). Fusing the Tel1 interaction domain from Xrs2 to Mre11-NLS is sufficient to restore telomere elongation and Tel1 signaling to Xrs2-deficient cells. Furthermore, Tel1 stabilizes Mre11-DNA association, and this stabilization function becomes important for DNA damage resistance in the absence of Xrs2. Enforcing Tel1 recruitment to the nuclear MR complex fully rescues end tethering and stalled replication fork stability, and suppresses GCRs, highlighting important roles for Xrs2 and Tel1 to ensure optimal MR activity.
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Affiliation(s)
- Julyun Oh
- Biological Sciences Program, Columbia University, New York, NY 10027, USA; Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - So Jung Lee
- Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Rodney Rothstein
- Biological Sciences Program, Columbia University, New York, NY 10027, USA; Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Lorraine S Symington
- Biological Sciences Program, Columbia University, New York, NY 10027, USA; Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, NY 10032, USA; Department of Genetics & Development, Columbia University Irving Medical Center, New York, NY 10032, USA.
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22
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HO Endonuclease-Initiated Recombination in Yeast Meiosis Fails To Promote Homologous Centromere Pairing and Is Not Constrained To Utilize the Dmc1 Recombinase. G3-GENES GENOMES GENETICS 2018; 8:3637-3659. [PMID: 30254180 PMCID: PMC6222578 DOI: 10.1534/g3.118.200641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Crossover recombination during meiosis is accompanied by a dramatic chromosome reorganization. In Saccharomyces cerevisiae, the onset of meiotic recombination by the Spo11 transesterase leads to stable pairwise associations between previously unassociated homologous centromeres followed by the intimate alignment of homologous axes via synaptonemal complex (SC) assembly. However, the molecular relationship between recombination and global meiotic chromosome reorganization remains poorly understood. In budding yeast, one question is why SC assembly initiates earliest at centromere regions while the DNA double strand breaks (DSBs) that initiate recombination occur genome-wide. We targeted the site-specific HO endonuclease to various positions on S. cerevisiae’s longest chromosome in order to ask whether a meiotic DSB’s proximity to the centromere influences its capacity to promote homologous centromere pairing and SC assembly. We show that repair of an HO-mediated DSB does not promote homologous centromere pairing nor any extent of SC assembly in spo11 meiotic nuclei, regardless of its proximity to the centromere. DSBs induced en masse by phleomycin exposure likewise do not promote homologous centromere pairing nor robust SC assembly. Interestingly, in contrast to Spo11, HO-initiated interhomolog recombination is not affected by loss of the meiotic kinase, Mek1, and is not constrained to use the meiosis-specific Dmc1 recombinase. These results strengthen the previously proposed idea that (at least some) Spo11 DSBs may be specialized in activating mechanisms that both 1) reinforce homologous chromosome alignment via homologous centromere pairing and SC assembly, and 2) establish Dmc1 as the primary strand exchange enzyme.
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23
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Hofstatter PG, Brown MW, Lahr DJG. Comparative Genomics Supports Sex and Meiosis in Diverse Amoebozoa. Genome Biol Evol 2018; 10:3118-3128. [PMID: 30380054 PMCID: PMC6263441 DOI: 10.1093/gbe/evy241] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2018] [Indexed: 12/30/2022] Open
Abstract
Sex and reproduction are often treated as a single phenomenon in animals and plants, as in these organisms reproduction implies mixis and meiosis. In contrast, sex and reproduction are independent biological phenomena that may or may not be linked in the majority of other eukaryotes. Current evidence supports a eukaryotic ancestor bearing a mating type system and meiosis, which is a process exclusive to eukaryotes. Even though sex is ancestral, the literature regarding life cycles of amoeboid lineages depicts them as asexual organisms. Why would loss of sex be common in amoebae, if it is rarely lost, if ever, in plants and animals, as well as in fungi? One way to approach the question of meiosis in the "asexuals" is to evaluate the patterns of occurrence of genes for the proteins involved in syngamy and meiosis. We have applied a comparative genomic approach to study the occurrence of the machinery for plasmogamy, karyogamy, and meiosis in Amoebozoa, a major amoeboid supergroup. Our results support a putative occurrence of syngamy and meiotic processes in all major amoebozoan lineages. We conclude that most amoebozoans may perform mixis, recombination, and ploidy reduction through canonical meiotic processes. The present evidence indicates the possibility of sexual cycles in many lineages traditionally held as asexual.
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Affiliation(s)
- Paulo G Hofstatter
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Brazil
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University
| | - Daniel J G Lahr
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Brazil
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24
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Interdependent and separable functions of Caenorhabditis elegans MRN-C complex members couple formation and repair of meiotic DSBs. Proc Natl Acad Sci U S A 2018; 115:E4443-E4452. [PMID: 29686104 DOI: 10.1073/pnas.1719029115] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Faithful inheritance of genetic information through sexual reproduction relies on the formation of crossovers between homologous chromosomes during meiosis, which, in turn, relies on the formation and repair of numerous double-strand breaks (DSBs). As DSBs pose a potential threat to the genome, mechanisms that ensure timely and error-free DSB repair are crucial for successful meiosis. Here, we identify NBS-1, the Caenorhabditis elegans ortholog of the NBS1 (mutated in Nijmegen Breakage Syndrome) subunit of the conserved MRE11-RAD50-NBS1/Xrs2 (MRN) complex, as a key mediator of DSB repair via homologous recombination (HR) during meiosis. Loss of nbs-1 leads to severely reduced loading of recombinase RAD-51, ssDNA binding protein RPA, and pro-crossover factor COSA-1 during meiotic prophase progression; aggregated and fragmented chromosomes at the end of meiotic prophase; and 100% progeny lethality. These phenotypes reflect a role for NBS-1 in processing of meiotic DSBs for HR that is shared with its interacting partners MRE-11-RAD-50 and COM-1 (ortholog of Com1/Sae2/CtIP). Unexpectedly, in contrast to MRE-11 and RAD-50, NBS-1 is not required for meiotic DSB formation. Meiotic defects of the nbs-1 mutant are partially suppressed by abrogation of the nonhomologous end-joining (NHEJ) pathway, indicating a role for NBS-1 in antagonizing NHEJ during meiosis. Our data further reveal that NBS-1 and COM-1 play distinct roles in promoting HR and antagonizing NHEJ. We propose a model in which different components of the MRN-C complex work together to couple meiotic DSB formation with efficient and timely engagement of HR, thereby ensuring crossover formation and restoration of genome integrity before the meiotic divisions.
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25
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26
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Wang Y, Jiang L, Zhang T, Jing J, He Y. ZmCom1 Is Required for Both Mitotic and Meiotic Recombination in Maize. FRONTIERS IN PLANT SCIENCE 2018; 9:1005. [PMID: 30061907 PMCID: PMC6055016 DOI: 10.3389/fpls.2018.01005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/20/2018] [Indexed: 05/02/2023]
Abstract
CtIP/Ctp1/Sae2/Com1, a highly conserved protein from yeast to higher eukaryotes, is required for DNA double-strand break repair through homologous recombination (HR). In this study, we identified and characterized the COM1 homolog in maize. The ZmCom1 gene is abundantly expressed in reproductive tissues at meiosis stages. In ZmCom1-deficient plants, meiotic chromosomes are constantly entangled as a formation of multivalents and accompanied with chromosome fragmentation at anaphase I. In addition, the formation of telomere bouquet, homologous pairing and synapsis were disturbed. The immunostaining assay showed that the localization of ASY1 and DSY2 was normal, while ZYP1 signals were severely disrupted in Zmcom1 meiocytes, indicating that ZmCom1 is critically required for the proper SC assembly. Moreover, RAD51 signals were almost completely absent in Zmcom1 meiocytes, implying that COM1 is required for RAD51 loading. Surprisingly, in contrast to the Atcom1 and Oscom1 mutants, Zmcom1 mutant plants exhibited a number of vegetative phenotypes under normal growth condition, which may be partly attributed to mitotic aberrations including chromosomal fragmentation and anaphase bridges. Taken together, our results suggest that although the roles of COM1 in HR process seem to be primarily conserved, the COM1 dysfunction can result in the marked dissimilarity in mitotic and meiotic outcomes in maize compared to Arabidopsis and rice. We suggest that this character may be related to the discrete genome context.
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27
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Sidhu GK, Warzecha T, Pawlowski WP. Evolution of meiotic recombination genes in maize and teosinte. BMC Genomics 2017; 18:106. [PMID: 28122517 PMCID: PMC5267385 DOI: 10.1186/s12864-017-3486-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 01/11/2017] [Indexed: 11/25/2022] Open
Abstract
Background Meiotic recombination is a major source of genetic variation in eukaryotes. The role of recombination in evolution is recognized but little is known about how evolutionary forces affect the recombination pathway itself. Although the recombination pathway is fundamentally conserved across different species, genetic variation in recombination components and outcomes has been observed. Theoretical predictions and empirical studies suggest that changes in the recombination pathway are likely to provide adaptive abilities to populations experiencing directional or strong selection pressures, such as those occurring during species domestication. We hypothesized that adaptive changes in recombination may be associated with adaptive evolution patterns of genes involved in meiotic recombination. Results To examine how maize evolution and domestication affected meiotic recombination genes, we studied patterns of sequence polymorphism and divergence in eleven genes controlling key steps in the meiotic recombination pathway in a diverse set of maize inbred lines and several accessions of teosinte, the wild ancestor of maize. We discovered that, even though the recombination genes generally exhibited high sequence conservation expected in a pathway controlling a key cellular process, they showed substantial levels and diverse patterns of sequence polymorphism. Among others, we found differences in sequence polymorphism patterns between tropical and temperate maize germplasms. Several recombination genes displayed patterns of polymorphism indicative of adaptive evolution. Conclusions Despite their ancient origin and overall sequence conservation, meiotic recombination genes can exhibit extensive and complex patterns of molecular evolution. Changes in these genes could affect the functioning of the recombination pathway, and may have contributed to the successful domestication of maize and its expansion to new cultivation areas. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3486-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gaganpreet K Sidhu
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA.,Current address: Institute for Cancer Genetics, Columbia University, New York, NY, 10032, USA
| | - Tomasz Warzecha
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA.,Permanent address: Department of Plant Breeding and Seed Science, Agricultural University, Krakow, Poland
| | - Wojciech P Pawlowski
- School of Integrative Plant Science, Cornell University, Ithaca, NY, 14853, USA.
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28
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Personalised Medicine: Genome Maintenance Lessons Learned from Studies in Yeast as a Model Organism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1007:157-178. [PMID: 28840557 DOI: 10.1007/978-3-319-60733-7_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Yeast research has been tremendously contributing to the understanding of a variety of molecular pathways due to the ease of its genetic manipulation, fast doubling time as well as being cost-effective. The understanding of these pathways did not only help scientists learn more about the cellular functions but also assisted in deciphering the genetic and cellular defects behind multiple diseases. Hence, yeast research not only opened the doors for transforming basic research into applied research, but also paved the roads for improving diagnosis and innovating personalized therapy of different diseases. In this chapter, we discuss how yeast research has contributed to understanding major genome maintenance pathways such as the S-phase checkpoint activation pathways, repair via homologous recombination and non-homologous end joining as well as topoisomerases-induced protein linked DNA breaks repair. Defects in these pathways lead to neurodegenerative diseases and cancer. Thus, the understanding of the exact genetic defects underlying these diseases allowed the development of personalized medicine, improving the diagnosis and treatment and overcoming the detriments of current conventional therapies such as the side effects, toxicity as well as drug resistance.
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29
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The Slavic NBN Founder Mutation: A Role for Reproductive Fitness? PLoS One 2016; 11:e0167984. [PMID: 27936167 PMCID: PMC5148078 DOI: 10.1371/journal.pone.0167984] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 11/23/2016] [Indexed: 01/21/2023] Open
Abstract
The vast majority of patients with Nijmegen Breakage Syndrome (NBS) are of Slavic origin and carry a deleterious deletion (c.657del5; rs587776650) in the NBN gene on chromosome 8q21. This mutation is essentially confined to Slavic populations and may thus be considered a Slavic founder mutation. Notably, not a single parenthood of a homozygous c.657del5 carrier has been reported to date, while heterozygous carriers do reproduce but have an increased cancer risk. These observations seem to conflict with the considerable carrier frequency of c.657del5 of 0.5% to 1% as observed in different Slavic populations because deleterious mutations would be eliminated quite rapidly by purifying selection. Therefore, we propose that heterozygous c.657del5 carriers have increased reproductive success, i.e., that the mutation confers heterozygote advantage. In fact, in our cohort study of the reproductive history of 24 NBS pedigrees from the Czech Republic, we observed that female carriers gave birth to more children on average than female non-carriers, while no such reproductive differences were observed for males. We also estimate that c.657del5 likely occurred less than 300 generations ago, thus supporting the view that the original mutation predated the historic split and subsequent spread of the ‘Slavic people’. We surmise that the higher fertility of female c.657del5 carriers reflects a lower miscarriage rate in these women, thereby reflecting the role of the NBN gene product, nibrin, in the repair of DNA double strand breaks and their processing in immune gene rearrangements, telomere maintenance, and meiotic recombination, akin to the previously described role of the DNA repair genes BRCA1 and BRCA2.
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30
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Xu Z, Song Z, Li G, Tu H, Liu W, Liu Y, Wang P, Wang Y, Cui X, Liu C, Shang Y, de Rooij DG, Gao F, Li W. H2B ubiquitination regulates meiotic recombination by promoting chromatin relaxation. Nucleic Acids Res 2016; 44:9681-9697. [PMID: 27431324 PMCID: PMC5175339 DOI: 10.1093/nar/gkw652] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Accepted: 07/11/2016] [Indexed: 12/22/2022] Open
Abstract
Meiotic recombination is essential for fertility in most sexually reproducing species, but the molecular mechanisms underlying this process remain poorly understood in mammals. Here, we show that RNF20-mediated H2B ubiquitination is required for meiotic recombination. A germ cell-specific knockout of the H2B ubiquitination E3 ligase RNF20 results in complete male infertility. The Stra8-Rnf20−/− spermatocytes arrest at the pachytene stage because of impaired programmed double-strand break (DSB) repair. Further investigations reveal that the depletion of RNF20 in the germ cells affects chromatin relaxation, thus preventing programmed DSB repair factors from being recruited to proper positions on the chromatin. The gametogenetic defects of the H2B ubiquitination deficient cells could be partially rescued by forced chromatin relaxation. Taken together, our results demonstrate that RNF20/Bre1p-mediated H2B ubiquitination regulates meiotic recombination by promoting chromatin relaxation, and suggest an old drug may provide a new way to treat some oligo- or azoospermia patients with chromatin relaxation disorders.
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Affiliation(s)
- Zhiliang Xu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenhua Song
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Guoping Li
- The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, Beijing 100730, China
| | - Huayu Tu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Weixiao Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yujiao Liu
- College of Marine Life, Ocean University of China, Qingdao 266003, China
| | - Pan Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuanting Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Xiuhong Cui
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Chao Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yongliang Shang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.,University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Dirk G de Rooij
- Reproductive Biology Group, Division of Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 Utrecht, the Netherlands
| | - Fei Gao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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Šamanić I, Cvitanić R, Simunić J, Puizina J. Arabidopsis thalianaMRE11 is essential for activation of cell cycle arrest, transcriptional regulation and DNA repair upon the induction of double-stranded DNA breaks. PLANT BIOLOGY (STUTTGART, GERMANY) 2016; 18:681-694. [PMID: 27007017 DOI: 10.1111/plb.12453] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 03/18/2016] [Indexed: 06/05/2023]
Abstract
Given the fundamental role of MRE11 in many aspects of DNA metabolism and signalling in eukaryotes, we analysed the impact of several MRE11 mutations on DNA damage response (DDR) and DNA repair in Arabidopsis thaliana. Three different atmre11 and an atatm-2 mutant lines, together with the wild type (WT), were compared using a new Arabidopsis genotoxic assay for in situ evaluation of genome integrity and DNA damage repair efficiency after double strand break (DSB) induction. The results showed that, despite the phenotypic differences and different lengths of the putative truncated AtMRE11 proteins, all three atmre11 and the atatm-2 mutant lines exhibited common hypersensitivity to bleomycin treatment, where they only slightly reduced mitotic activity, indicating a G2/M checkpoint abrogation. In contrast to the WT, which reduced the frequency of chromosomal aberrations throughout the recovery period after treatment, none of the three atmre11 and atatm-2 mutants recovered. Moreover, atmre11-3 mutants, similarly to atatm-2 mutants, failed to transcriptionally induce several DDR genes and had altered expression of the CYCB1;1::GUS protein. Nevertheless, numerous chromosomal fusions in the atmre11 mutants, observed after DNA damage induction, suggest intensive DNA repair activity. These results indicate that functional and full-length AtMRE11 is essential for activation of the cell cycle arrest, transcriptional regulation and DNA repair upon induction of DSB.
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Affiliation(s)
- I Šamanić
- Department of Biology, Faculty of Science, University of Split, Split, Croatia
| | - R Cvitanić
- Department of Biology, Faculty of Science, University of Split, Split, Croatia
| | - J Simunić
- Ruđer Bošković Institute, Zagreb, Croatia
| | - J Puizina
- Department of Biology, Faculty of Science, University of Split, Split, Croatia
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32
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Dbl2 Regulates Rad51 and DNA Joint Molecule Metabolism to Ensure Proper Meiotic Chromosome Segregation. PLoS Genet 2016; 12:e1006102. [PMID: 27304859 PMCID: PMC4909299 DOI: 10.1371/journal.pgen.1006102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 05/12/2016] [Indexed: 11/19/2022] Open
Abstract
To identify new proteins required for faithful meiotic chromosome segregation, we screened a Schizosaccharomyces pombe deletion mutant library and found that deletion of the dbl2 gene led to missegregation of chromosomes during meiosis. Analyses of both live and fixed cells showed that dbl2Δ mutant cells frequently failed to segregate homologous chromosomes to opposite poles during meiosis I. Removing Rec12 (Spo11 homolog) to eliminate meiotic DNA double-strand breaks (DSBs) suppressed the segregation defect in dbl2Δ cells, indicating that Dbl2 acts after the initiation of meiotic recombination. Analyses of DSBs and Holliday junctions revealed no significant defect in their formation or processing in dbl2Δ mutant cells, although some Rec12-dependent DNA joint molecules persisted late in meiosis. Failure to segregate chromosomes in the absence of Dbl2 correlated with persistent Rad51 foci, and deletion of rad51 or genes encoding Rad51 mediators also suppressed the segregation defect of dbl2Δ. Formation of foci of Fbh1, an F-box helicase that efficiently dismantles Rad51-DNA filaments, was impaired in dbl2Δ cells. Our results suggest that Dbl2 is a novel regulator of Fbh1 and thereby Rad51-dependent DSB repair required for proper meiotic chromosome segregation and viable sex cell formation. The wide conservation of these proteins suggests that our results apply to many species. Meiosis produces haploid gametes from diploid precursor cells. This reduction of chromosome number is achieved by two successive divisions after only a single round of DNA replication. To identify novel regulators of meiosis, we screened a library of fission yeast deletion mutants and found that deletion of the dbl2 gene led to missegregation of chromosomes during meiosis. Analysis of live dbl2Δ cells by fluorescence microscopy showed that chromosomes frequently failed to segregate during the first meiotic division. Further cytological and biochemical analyses revealed that this segregation defect is due to persistent intermediates of DNA double-strand break repair, also called DNA joint molecules. Our results indicate that Dbl2 is required for formation of Fbh1 DNA helicase foci at the sites of DNA double-strand break repair in order to process DNA joint molecules and allow segregation of chromosomes during meiotic divisions. Our bioinformatics searches revealed that Dbl2 is highly conserved in fungi, animals and plants, suggesting that Dbl2 plays a similar role in other organisms–the formation of viable sex cells and healthy progeny.
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33
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The p53-like Protein CEP-1 Is Required for Meiotic Fidelity in C. elegans. Curr Biol 2016; 26:1148-58. [PMID: 27151662 DOI: 10.1016/j.cub.2016.03.036] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 02/05/2016] [Accepted: 03/14/2016] [Indexed: 11/21/2022]
Abstract
The passage of genetic information during meiosis requires exceptionally high fidelity to prevent birth defects and infertility. Accurate chromosome segregation during the first meiotic division relies on the formation of crossovers between homologous chromosomes and a series of precisely controlled steps to exchange genetic information. Many studies have hinted at a role for p53 in meiosis, but how it functions in this process is poorly understood. Here, we have identified a cooperative role for the p53-like protein CEP-1 and the meiotic protein HIM-5 in maintaining genome stability in the C. elegans germline. Loss of cep-1 and him-5 results in synthetic lethality that is dependent on the upstream DNA damage checkpoint but independent of the downstream core apoptotic pathway. We show that this synthetic lethality is the result of defective crossover formation due to reduced SPO-11-dependent double-strand breaks. Using cep-1 separation-of-function alleles, we show that cep-1 and him-5 also suppress inappropriate activation of the nonhomologous end joining (NHEJ) pathway. This work reveals an ancestral function for the p53 family in ensuring the fidelity of meiosis and establishes CEP-1 as a critical determinant of repair pathway choice.
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34
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Chen YJ, Chuang YC, Chuang CN, Cheng YH, Chang CR, Leng CH, Wang TF. S. cerevisiae Mre11 recruits conjugated SUMO moieties to facilitate the assembly and function of the Mre11-Rad50-Xrs2 complex. Nucleic Acids Res 2016; 44:2199-213. [PMID: 26743002 PMCID: PMC4797280 DOI: 10.1093/nar/gkv1523] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 12/19/2015] [Indexed: 01/04/2023] Open
Abstract
Double-strand breaks (DSBs) in chromosomes are the most challenging type of DNA damage. The yeast and mammalian Mre11-Rad50-Xrs2/Nbs1 (MRX/N)-Sae2/Ctp1 complex catalyzes the resection of DSBs induced by secondary structures, chemical adducts or covalently-attached proteins. MRX/N also initiates two parallel DNA damage responses-checkpoint phosphorylation and global SUMOylation-to boost a cell's ability to repair DSBs. However, the molecular mechanism of this SUMO-mediated response is not completely known. In this study, we report that Saccharomyces cerevisiae Mre11 can non-covalently recruit the conjugated SUMO moieties, particularly the poly-SUMO chain. Mre11 has two evolutionarily-conserved SUMO-interacting motifs, Mre11(SIM1) and Mre11(SIM2), which reside on the outermost surface of Mre11. Mre11(SIM1) is indispensable for MRX assembly. Mre11(SIM2) non-covalently links MRX with the SUMO enzymes (E2/Ubc9 and E3/Siz2) to promote global SUMOylation of DNA repair proteins. Mre11(SIM2) acts independently of checkpoint phosphorylation. During meiosis, the mre11(SIM2) mutant, as for mre11S, rad50S and sae2Δ, allows initiation but not processing of Spo11-induced DSBs. Using MRX and DSB repair as a model, our work reveals a general principle in which the conjugated SUMO moieties non-covalently facilitate the assembly and functions of multi-subunit protein complexes.
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Affiliation(s)
- Yu-Jie Chen
- Graduate Program of Biotechnology in Medicine, National Tsing Hua University and National Health Research Institutes, Taiwan Institute of Biotechnology, National Tsing Hua University, Hsinchu 300, Taiwan National Institute of Infectious Diseases and Vaccinology, National Health Research Institute, Miaoli 350, Taiwan Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Yu-Chien Chuang
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Chi-Ning Chuang
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Yun-Hsin Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Chuang-Rung Chang
- Graduate Program of Biotechnology in Medicine, National Tsing Hua University and National Health Research Institutes, Taiwan Institute of Biotechnology, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Chih-Hsiang Leng
- Graduate Program of Biotechnology in Medicine, National Tsing Hua University and National Health Research Institutes, Taiwan National Institute of Infectious Diseases and Vaccinology, National Health Research Institute, Miaoli 350, Taiwan
| | - Ting-Fang Wang
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
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Abstract
During meiotic recombination, double-strand breaks (DSBs) are formed in chromosomal DNA and then repaired as either crossovers (COs) or non-crossovers (NCOs). In most taxa, the number of DSBs vastly exceeds the number of COs. COs are required for generating genetic diversity in the progeny, as well as proper chromosome segregation. Their formation is tightly controlled so that there is at least one CO per pair of homologous chromosomes whereas the maximum number of COs per chromosome pair is fairly limited. One of the main mechanisms controlling the number of recombination events per meiosis is CO homeostasis, which maintains a stable CO number even when the DSB number is dramatically altered. The existence of CO homeostasis has been reported in several species, including mouse, yeast, and Caenorhabditis elegans. However, it is not known whether homeostasis exists in the same form in all species. In addition, the studies of homeostasis have been conducted using mutants and/or transgenic lines exhibiting fairly severe meiotic phenotypes, and it is unclear how important homeostasis is under normal physiological conditions. We found that, in maize, CO control is robust only to ensure one CO per chromosome pair. However, once this limit is reached, the CO number is linearly related to the DSB number. We propose that CO control is a multifaceted process whose different aspects have a varying degree of importance in different species.
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Ribeiro J, Abby E, Livera G, Martini E. RPA homologs and ssDNA processing during meiotic recombination. Chromosoma 2015; 125:265-76. [PMID: 26520106 PMCID: PMC4830875 DOI: 10.1007/s00412-015-0552-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 09/12/2015] [Accepted: 10/14/2015] [Indexed: 11/25/2022]
Abstract
Meiotic homologous recombination is a specialized process that involves homologous chromosome pairing and strand exchange to guarantee proper chromosome segregation and genetic diversity. The formation and repair of DNA double-strand breaks (DSBs) during meiotic recombination differs from those during mitotic recombination in that the homologous chromosome rather than the sister chromatid is the preferred repair template. The processing of single-stranded DNA (ssDNA) formed on intermediate recombination structures is central to driving the specific outcomes of DSB repair during meiosis. Replication protein A (RPA) is the main ssDNA-binding protein complex involved in DNA metabolism. However, the existence of RPA orthologs in plants and the recent discovery of meiosis specific with OB domains (MEIOB), a widely conserved meiosis-specific RPA1 paralog, strongly suggest that multiple RPA complexes evolved and specialized to subdivide their roles during DNA metabolism. Here we review ssDNA formation and maturation during mitotic and meiotic recombination underlying the meiotic specific features. We describe and discuss the existence and properties of MEIOB and multiple RPA subunits in plants and highlight how they can provide meiosis-specific fates to ssDNA processing during homologous recombination. Understanding the functions of these RPA homologs and how they interact with the canonical RPA subunits is of major interest in the fields of meiosis and DNA repair.
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Affiliation(s)
- Jonathan Ribeiro
- Laboratory of Development of the Gonads, Unit of Stem Cells and Radiation, University of Paris Diderot, Sorbonne Paris Cité, UMR 967, F-92265, Fontenay-aux-Roses, France
- CEA, DSV, iRCM, SCSR, LDG, F-92265, Fontenay-aux-Roses, France
- INSERM, Unité 967, F-92265, Fontenay-aux-Roses, France
- Université Paris-Saclay, UMR-967, F-92265, Fontenay-aux-Roses, France
| | - Emilie Abby
- Laboratory of Development of the Gonads, Unit of Stem Cells and Radiation, University of Paris Diderot, Sorbonne Paris Cité, UMR 967, F-92265, Fontenay-aux-Roses, France
- CEA, DSV, iRCM, SCSR, LDG, F-92265, Fontenay-aux-Roses, France
- INSERM, Unité 967, F-92265, Fontenay-aux-Roses, France
- Université Paris-Saclay, UMR-967, F-92265, Fontenay-aux-Roses, France
| | - Gabriel Livera
- Laboratory of Development of the Gonads, Unit of Stem Cells and Radiation, University of Paris Diderot, Sorbonne Paris Cité, UMR 967, F-92265, Fontenay-aux-Roses, France
- CEA, DSV, iRCM, SCSR, LDG, F-92265, Fontenay-aux-Roses, France
- INSERM, Unité 967, F-92265, Fontenay-aux-Roses, France
- Université Paris-Saclay, UMR-967, F-92265, Fontenay-aux-Roses, France
| | - Emmanuelle Martini
- Laboratory of Development of the Gonads, Unit of Stem Cells and Radiation, University of Paris Diderot, Sorbonne Paris Cité, UMR 967, F-92265, Fontenay-aux-Roses, France.
- CEA, DSV, iRCM, SCSR, LDG, F-92265, Fontenay-aux-Roses, France.
- INSERM, Unité 967, F-92265, Fontenay-aux-Roses, France.
- Université Paris-Saclay, UMR-967, F-92265, Fontenay-aux-Roses, France.
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Pandey R, Mohmmed A, Pierrot C, Khalife J, Malhotra P, Gupta D. Genome wide in silico analysis of Plasmodium falciparum phosphatome. BMC Genomics 2014; 15:1024. [PMID: 25425018 PMCID: PMC4256932 DOI: 10.1186/1471-2164-15-1024] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 11/12/2014] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Eukaryotic cellular machineries are intricately regulated by several molecular mechanisms involving transcriptional control, post-translational control and post-translational modifications of proteins (PTMs). Reversible protein phosphorylation/dephosphorylation process, which involves kinases as well as phosphatases, represents an important regulatory mechanism for diverse pathways and systems in all organisms including human malaria parasite, Plasmodium falciparum. Earlier analysis on P. falciparum protein-phosphatome revealed presence of 34 phosphatases in Plasmodium genome. Recently, we re-analysed P. falciparum phosphatome aimed at identifying parasite specific phosphatases. RESULTS Plasmodium database (PlasmoDB 9.2) search, combined with PFAM and CDD searches, revealed 67 candidate phosphatases in P. falciparum. While this number is far less than the number of phosphatases present in Homo sapiens, it is almost the same as in other Plasmodium species. These Plasmodium phosphatase proteins were classified into 13 super families based on NCBI CDD search. Analysis of proteins expression profiles of the 67 phosphatases revealed that 44 phosphatases are expressed in both schizont as well as gametocytes stages. Fourteen phosphatases are common in schizont, ring and trophozoite stages, four phosphatases are restricted to gametocytes, whereas another three restricted to schizont stage. The phylogenetic trees for each of the known phosphatase super families reveal a considerable phylogenetic closeness amongst apicomplexan organisms and a considerable phylogenetic distance with other eukaryotic model organisms included in the study. The GO assignments and predicted interaction partners of the parasite phosphatases indicate its important role in diverse cellular processes. CONCLUSION In the study presented here, we reviewed the P. falciparum phosphatome to show presence of 67 candidate phosphatases in P. falciparum genomes/proteomes. Intriguingly, amongst these phosphatases, we could identify six Plasmodium specific phosphatases and 33 putative phosphatases that do not have human orthologs, thereby suggesting that these phosphatases have the potential to be explored as novel antimalarial drug targets.
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Affiliation(s)
| | | | | | - Jamal Khalife
- Structural and Computational Biology group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India.
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Paull TT, Deshpande RA. The Mre11/Rad50/Nbs1 complex: recent insights into catalytic activities and ATP-driven conformational changes. Exp Cell Res 2014; 329:139-47. [PMID: 25016281 PMCID: PMC4252570 DOI: 10.1016/j.yexcr.2014.07.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 07/01/2014] [Indexed: 10/25/2022]
Abstract
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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Affiliation(s)
- Tanya T Paull
- The Howard Hughes Medical Institute, The Department of Molecular Biosciences, The Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA.
| | - Rajashree A Deshpande
- The Howard Hughes Medical Institute, The Department of Molecular Biosciences, The Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA
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Lam I, Keeney S. Mechanism and regulation of meiotic recombination initiation. Cold Spring Harb Perspect Biol 2014; 7:a016634. [PMID: 25324213 DOI: 10.1101/cshperspect.a016634] [Citation(s) in RCA: 290] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Meiotic recombination involves the formation and repair of programmed DNA double-strand breaks (DSBs) catalyzed by the conserved Spo11 protein. This review summarizes recent studies pertaining to the formation of meiotic DSBs, including the mechanism of DNA cleavage by Spo11, proteins required for break formation, and mechanisms that control the location, timing, and number of DSBs. Where appropriate, findings in different organisms are discussed to highlight evolutionary conservation or divergence.
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Affiliation(s)
- Isabel Lam
- Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, New York 10065 Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065
| | - Scott Keeney
- Louis V. Gerstner Jr. Graduate School of Biomedical Sciences, Memorial Sloan Kettering Cancer Center, New York, New York 10065 Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065 Howard Hughes Medical Institute, Memorial Sloan Kettering Cancer Center, New York, New York 10065
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40
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Marmignon A, Bischerour J, Silve A, Fojcik C, Dubois E, Arnaiz O, Kapusta A, Malinsky S, Bétermier M. Ku-mediated coupling of DNA cleavage and repair during programmed genome rearrangements in the ciliate Paramecium tetraurelia. PLoS Genet 2014; 10:e1004552. [PMID: 25166013 PMCID: PMC4148214 DOI: 10.1371/journal.pgen.1004552] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 06/19/2014] [Indexed: 11/19/2022] Open
Abstract
During somatic differentiation, physiological DNA double-strand breaks (DSB) can drive programmed genome rearrangements (PGR), during which DSB repair pathways are mobilized to safeguard genome integrity. Because of their unique nuclear dimorphism, ciliates are powerful unicellular eukaryotic models to study the mechanisms involved in PGR. At each sexual cycle, the germline nucleus is transmitted to the progeny, but the somatic nucleus, essential for gene expression, is destroyed and a new somatic nucleus differentiates from a copy of the germline nucleus. In Paramecium tetraurelia, the development of the somatic nucleus involves massive PGR, including the precise elimination of at least 45,000 germline sequences (Internal Eliminated Sequences, IES). IES excision proceeds through a cut-and-close mechanism: a domesticated transposase, PiggyMac, is essential for DNA cleavage, and DSB repair at excision sites involves the Ligase IV, a specific component of the non-homologous end-joining (NHEJ) pathway. At the genome-wide level, a huge number of programmed DSBs must be repaired during this process to allow the assembly of functional somatic chromosomes. To understand how DNA cleavage and DSB repair are coordinated during PGR, we have focused on Ku, the earliest actor of NHEJ-mediated repair. Two Ku70 and three Ku80 paralogs are encoded in the genome of P. tetraurelia: Ku70a and Ku80c are produced during sexual processes and localize specifically in the developing new somatic nucleus. Using RNA interference, we show that the development-specific Ku70/Ku80c heterodimer is essential for the recovery of a functional somatic nucleus. Strikingly, at the molecular level, PiggyMac-dependent DNA cleavage is abolished at IES boundaries in cells depleted for Ku80c, resulting in IES retention in the somatic genome. PiggyMac and Ku70a/Ku80c co-purify as a complex when overproduced in a heterologous system. We conclude that Ku has been integrated in the Paramecium DNA cleavage factory, enabling tight coupling between DSB introduction and repair during PGR. DNA double-strand breaks (DSBs) are potential threats for chromosome stability, but they are usually repaired by two major pathways, homologous recombination or non-homologous end joining (NHEJ). DSBs can also be essential during physiological processes, such as the programmed removal of germline sequences that takes place in various eukaryotes, including ciliates, during somatic differentiation. We use the ciliate Paramecium tetraurelia as a unicellular model to study how DNA breakage and DSB repair are coordinated during programmed genome rearrangements. In this organism, assembly of the somatic genome involves the elimination of ∼25% of germline DNA, including the precise excision of thousands of short Internal Eliminated Sequences (IES) scattered along germline chromosomes. A domesticated piggyBac transposase, PiggyMac, is required for double-strand DNA cleavage at IES ends and IES excision sites are very precisely repaired by the NHEJ pathway. Here, we report that a specialized Ku heterodimer, specifically expressed during programmed genome rearrangements, is an essential partner of PiggyMac and activates DNA cleavage. We propose that incorporation of DSB repair proteins in a pre-cleavage complex constitutes a safe and efficient way for Paramecium to direct thousands of programmed DSBs to the NHEJ pathway and make sure that somatic chromosomes are assembled correctly.
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Affiliation(s)
- Antoine Marmignon
- CNRS UPR3404 Centre de Génétique Moléculaire, Gif-sur-Yvette, France; Université Paris-Sud, Département de Biologie, Orsay, France
| | - Julien Bischerour
- CNRS UPR3404 Centre de Génétique Moléculaire, Gif-sur-Yvette, France; Université Paris-Sud, Département de Biologie, Orsay, France
| | - Aude Silve
- CNRS UPR3404 Centre de Génétique Moléculaire, Gif-sur-Yvette, France; Université Paris-Sud, Département de Biologie, Orsay, France
| | - Clémentine Fojcik
- CNRS UPR3404 Centre de Génétique Moléculaire, Gif-sur-Yvette, France; Université Paris-Sud, Département de Biologie, Orsay, France
| | - Emeline Dubois
- CNRS UPR3404 Centre de Génétique Moléculaire, Gif-sur-Yvette, France; Université Paris-Sud, Département de Biologie, Orsay, France
| | - Olivier Arnaiz
- CNRS UPR3404 Centre de Génétique Moléculaire, Gif-sur-Yvette, France; Université Paris-Sud, Département de Biologie, Orsay, France
| | - Aurélie Kapusta
- CNRS UPR3404 Centre de Génétique Moléculaire, Gif-sur-Yvette, France; Université Paris-Sud, Département de Biologie, Orsay, France
| | - Sophie Malinsky
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, Paris, France; INSERM, U1024, Paris, France; CNRS, UMR 8197, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, UFR Sciences du Vivant, Paris, France
| | - Mireille Bétermier
- CNRS UPR3404 Centre de Génétique Moléculaire, Gif-sur-Yvette, France; Université Paris-Sud, Département de Biologie, Orsay, France
- * E-mail:
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Herdendorf TJ, Nelson SW. Catalytic mechanism of bacteriophage T4 Rad50 ATP hydrolysis. Biochemistry 2014; 53:5647-60. [PMID: 25137526 DOI: 10.1021/bi500558d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Spontaneous double-strand breaks (DSBs) are one of the most deleterious forms of DNA damage, and their improper repair can lead to cellular dysfunction. The Mre11 and Rad50 proteins, a nuclease and an ATPase, respectively, form a well-conserved complex that is involved in the initial processing of DSBs. Here we examine the kinetic and catalytic mechanism of ATP hydrolysis by T4 Rad50 (gp46) in the presence and absence of Mre11 (gp47) and DNA. Single-turnover and pre-steady state kinetics on the wild-type protein indicate that the rate-limiting step for Rad50, the MR complex, and the MR-DNA complex is either chemistry or a conformational change prior to catalysis. Pre-steady state product release kinetics, coupled with viscosity steady state kinetics, also supports that the binding of DNA to the MR complex does not alter the rate-limiting step. The lack of a positive deuterium solvent isotope effect for the wild type and several active site mutants, combined with pH-rate profiles, implies that chemistry is rate-limiting and the ATPase mechanism proceeds via an asymmetric, dissociative-like transition state. Mutation of the Walker A/B and H-loop residues also affects the allosteric communication between Rad50 active sites, suggesting possible routes for cooperativity between the ATP active sites.
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Affiliation(s)
- Timothy J Herdendorf
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University , Ames, Iowa 50011, United States
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42
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de Massy B. Initiation of meiotic recombination: how and where? Conservation and specificities among eukaryotes. Annu Rev Genet 2014; 47:563-99. [PMID: 24050176 DOI: 10.1146/annurev-genet-110711-155423] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Meiotic recombination is essential for fertility in most sexually reproducing species. This process also creates new combinations of alleles and has important consequences for genome evolution. Meiotic recombination is initiated by the formation of DNA double-strand breaks (DSBs), which are repaired by homologous recombination. DSBs are catalyzed by the evolutionarily conserved SPO11 protein, assisted by several other factors. Some of them are absolutely required, whereas others are needed only for full levels of DSB formation and may participate in the regulation of DSB timing and frequency as well as the coordination between DSB formation and repair. The sites where DSBs occur are not randomly distributed in the genome, and remarkably distinct strategies have emerged to control their localization in different species. Here, I review the recent advances in the components required for DSB formation and localization in the various model organisms in which these studies have been performed.
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Affiliation(s)
- Bernard de Massy
- Institute of Human Genetics, Centre National de la Recherché Scientifique, UPR1142, 34396 Montpellier, France;
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43
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Zamariola L, Tiang CL, De Storme N, Pawlowski W, Geelen D. Chromosome segregation in plant meiosis. FRONTIERS IN PLANT SCIENCE 2014; 5:279. [PMID: 24987397 PMCID: PMC4060054 DOI: 10.3389/fpls.2014.00279] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 05/28/2014] [Indexed: 05/18/2023]
Abstract
Faithful chromosome segregation in meiosis is essential for ploidy stability over sexual life cycles. In plants, defective chromosome segregation caused by gene mutations or other factors leads to the formation of unbalanced or unreduced gametes creating aneuploid or polyploid progeny, respectively. Accurate segregation requires the coordinated execution of conserved processes occurring throughout the two meiotic cell divisions. Synapsis and recombination ensure the establishment of chiasmata that hold homologous chromosomes together allowing their correct segregation in the first meiotic division, which is also tightly regulated by cell-cycle dependent release of cohesin and monopolar attachment of sister kinetochores to microtubules. In meiosis II, bi-orientation of sister kinetochores and proper spindle orientation correctly segregate chromosomes in four haploid cells. Checkpoint mechanisms acting at kinetochores control the accuracy of kinetochore-microtubule attachment, thus ensuring the completion of segregation. Here we review the current knowledge on the processes taking place during chromosome segregation in plant meiosis, focusing on the characterization of the molecular factors involved.
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Affiliation(s)
- Linda Zamariola
- Department of Plant Production, Faculty of Bioscience Engineering, University of GhentGhent, Belgium
| | - Choon Lin Tiang
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA
| | - Nico De Storme
- Department of Plant Production, Faculty of Bioscience Engineering, University of GhentGhent, Belgium
| | - Wojtek Pawlowski
- Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY, USA
| | - Danny Geelen
- Department of Plant Production, Faculty of Bioscience Engineering, University of GhentGhent, Belgium
- *Correspondence: Danny Geelen, Department of Plant Production, Faculty of Bioscience Engineering, University of Ghent, Coupure Links 653, 9000 Ghent, Belgium e-mail:
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44
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De Storme N, Geelen D. The impact of environmental stress on male reproductive development in plants: biological processes and molecular mechanisms. PLANT, CELL & ENVIRONMENT 2014; 37:1-18. [PMID: 23731015 PMCID: PMC4280902 DOI: 10.1111/pce.12142] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 04/30/2013] [Accepted: 05/08/2013] [Indexed: 05/18/2023]
Abstract
In plants, male reproductive development is extremely sensitive to adverse climatic environments and (a)biotic stress. Upon exposure to stress, male gametophytic organs often show morphological, structural and metabolic alterations that typically lead to meiotic defects or premature spore abortion and male reproductive sterility. Depending on the type of stress involved (e.g. heat, cold, drought) and the duration of stress exposure, the underlying cellular defect is highly variable and either involves cytoskeletal alterations, tapetal irregularities, altered sugar utilization, aberrations in auxin metabolism, accumulation of reactive oxygen species (ROS; oxidative stress) or the ectopic induction of programmed cell death (PCD). In this review, we present the critically stress-sensitive stages of male sporogenesis (meiosis) and male gametogenesis (microspore development), and discuss the corresponding biological processes involved and the resulting alterations in male reproduction. In addition, this review also provides insights into the molecular and/or hormonal regulation of the environmental stress sensitivity of male reproduction and outlines putative interaction(s) between the different processes involved.
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Affiliation(s)
- Nico De Storme
- Department of Plant Production, Faculty of Bioscience Engineering, University of Ghent, Coupure Links, 653, B-9000, Ghent, Belgium
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45
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Evidence for distinct functions of MRE11 in Arabidopsis meiosis. PLoS One 2013; 8:e78760. [PMID: 24205310 PMCID: PMC3804616 DOI: 10.1371/journal.pone.0078760] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/22/2013] [Indexed: 01/09/2023] Open
Abstract
The evolutionary conserved Mre11/Rad50/Nbs1 complex functions as one of the guardians of genome integrity in eukaryotes; it is required for the double-strand break repair, meiosis, DNA checkpoint, and telomere maintenance. To better understand the role of the MRE11 gene in Arabidopsis, we performed comparative analysis of several mre11 alleles with respect to genome stability and meiosis. The mre11-4 and mre11-2 alleles presumably produce truncated MRE11 proteins composed of the first 499 and 529 amino acids, respectively. Although the putative MRE11 truncated proteins differ only by 30 amino acids, the mutants exhibited strikingly different phenotypes in regards to growth morphology, genome stability and meiosis. While the mre11-2 mutants are fully fertile and undergo normal meiosis, the mre11-4 plants are sterile due to aberrant repair of meiotic DNA breaks. Structural homology analysis suggests that the T-DNA insertion in the mre11-4 allele probably disrupted the putative RAD50 interaction and/or homodimerization domain, which is assumed to be preserved in mre11-2 allele. Intriguingly, introgression of the atm-2 mutant plant into the mre11-2 background renders the double mutant infertile, a phenotype not observed in either parent line. This data indicate that MRE11 partially compensates for ATM deficiency in meiosis of Arabidopsis.
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Ji J, Tang D, Wang M, Li Y, Zhang L, Wang K, Li M, Cheng Z. MRE11 is required for homologous synapsis and DSB processing in rice meiosis. Chromosoma 2013; 122:363-76. [PMID: 23793712 DOI: 10.1007/s00412-013-0421-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 05/23/2013] [Accepted: 06/07/2013] [Indexed: 11/26/2022]
Abstract
Mre11, a conserved protein found in organisms ranging from yeast to multicellular organisms, is required for normal meiotic recombination. Mre11 interacts with Rad50 and Nbs1/Xrs2 to form a complex (MRN/X) that participates in double-strand break (DSB) ends processing. In this study, we silenced the MRE11 gene in rice and detailed its function using molecular and cytological methods. The OsMRE11-deficient plants exhibited normal vegetative growth but could not set seed. Cytological analysis indicated that in the OsMRE11-deficient plants, homologous pairing was totally inhibited, and the chromosomes were completely entangled as a formation of multivalents at metaphase I, leading to the consequence of serious chromosome fragmentation during anaphase I. Immunofluorescence studies further demonstrated that OsMRE11 is required for homologous synapsis and DSB processing but is dispensable for meiotic DSB formation. We found that OsMRE11 protein was located on meiotic chromosomes from interphase to late pachytene. This protein showed normal localization in zep1, Oscom1 and Osmer3, as well as in OsSPO11-1(RNAi) plants, but not in pair2 and pair3 mutants. Taken together, our results provide evidence that OsMRE11 performs a function essential for maintaining the normal HR process and inhibiting non-homologous recombination during meiosis.
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Affiliation(s)
- Jianhui Ji
- State Key Laboratory of Plant Genomics and Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
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Potential role of meiosis proteins in melanoma chromosomal instability. J Skin Cancer 2013; 2013:190109. [PMID: 23840955 PMCID: PMC3694528 DOI: 10.1155/2013/190109] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 05/21/2013] [Indexed: 12/05/2022] Open
Abstract
Melanomas demonstrate chromosomal instability (CIN). In fact, CIN can be used to differentiate melanoma from benign nevi. The exact molecular mechanisms that drive CIN in melanoma have yet to be fully elucidated. Cancer/testis antigens are a unique group of germ cell proteins that are found to be primarily expressed in melanoma as compared to benign nevi. The abnormal expression of these germ cell proteins, normally expected only in the testis and ovaries, in somatic cells may lead to interference with normal cellular pathways. Germ cell proteins that may be particularly critical in CIN are meiosis proteins. Here, we review pathways unique to meiosis with a focus on how the aberrant expression of meiosis proteins in normal mitotic cells “meiomitosis” could impact chromosomal instability in melanoma and other cancers.
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Non-homologous end-joining pathway associated with occurrence of myocardial infarction: gene set analysis of genome-wide association study data. PLoS One 2013; 8:e56262. [PMID: 23457540 PMCID: PMC3574159 DOI: 10.1371/journal.pone.0056262] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 01/07/2013] [Indexed: 01/28/2023] Open
Abstract
PURPOSE DNA repair deficiencies have been postulated to play a role in the development and progression of cardiovascular disease (CVD). The hypothesis is that DNA damage accumulating with age may induce cell death, which promotes formation of unstable plaques. Defects in DNA repair mechanisms may therefore increase the risk of CVD events. We examined whether the joints effect of common genetic variants in 5 DNA repair pathways may influence the risk of CVD events. METHODS The PLINK set-based test was used to examine the association to myocardial infarction (MI) of the DNA repair pathway in GWAS data of 866 subjects of the GENetic DEterminants of Restenosis (GENDER) study and 5,244 subjects of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) study. We included the main DNA repair pathways (base excision repair, nucleotide excision repair, mismatch repair, homologous recombination and non-homologous end-joining (NHEJ)) in the analysis. RESULTS The NHEJ pathway was associated with the occurrence of MI in both GENDER (P = 0.0083) and PROSPER (P = 0.014). This association was mainly driven by genetic variation in the MRE11A gene (PGENDER = 0.0001 and PPROSPER = 0.002). The homologous recombination pathway was associated with MI in GENDER only (P = 0.011), for the other pathways no associations were observed. CONCLUSION This is the first study analyzing the joint effect of common genetic variation in DNA repair pathways and the risk of CVD events, demonstrating an association between the NHEJ pathway and MI in 2 different cohorts.
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Zhang J. The role of BRCA1 in homologous recombination repair in response to replication stress: significance in tumorigenesis and cancer therapy. Cell Biosci 2013; 3:11. [PMID: 23388117 PMCID: PMC3599463 DOI: 10.1186/2045-3701-3-11] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 12/20/2012] [Indexed: 12/16/2022] Open
Abstract
Germ line mutations in breast cancer gene 1 (BRCA1) predispose women to breast and ovarian cancers. Although BRCA1 is involved in many important biological processes, the function of BRCA1 in homologous recombination (HR) mediated repair is considered one of the major mechanisms contributing to its tumor suppression activity, and the cause of hypersensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors when BRCA1 is defective. Mounting evidence suggests that the mechanism of repairing DNA double strand breaks (DSBs) by HR is different than the mechanism operating when DNA replication is blocked. Although BRCA1 has been recognized as a central component in HR, the precise role of BRCA1 in HR, particularly under replication stress, has remained largely unknown. Given the fact that DNA lesions caused by replication blockages are the primary substrates for HR in mitotic cells, functional analysis of BRCA1 in HR repair in the context of replication stress should benefit our understanding of the molecular mechanisms underlying tumorigenesis associated with BRCA1 deficiencies, as well as the development of therapeutic approaches for cancer patients carrying BRCA1 mutations or reduced BRCA1 expression. This review focuses on the current advances in this setting and also discusses the significance in tumorigenesis and cancer therapy.
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Affiliation(s)
- Junran Zhang
- Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, BRB 323, Cleveland, OH, 44106, USA.
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Muñoz-Galván S, López-Saavedra A, Jackson SP, Huertas P, Cortés-Ledesma F, Aguilera A. Competing roles of DNA end resection and non-homologous end joining functions in the repair of replication-born double-strand breaks by sister-chromatid recombination. Nucleic Acids Res 2012; 41:1669-83. [PMID: 23254329 PMCID: PMC3561951 DOI: 10.1093/nar/gks1274] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
While regulating the choice between homologous recombination and non-homologous end joining (NHEJ) as mechanisms of double-strand break (DSB) repair is exerted at several steps, the key step is DNA end resection, which in Saccharomyces cerevisiae is controlled by the MRX complex and the Sgs1 DNA helicase or the Sae2 and Exo1 nucleases. To assay the role of DNA resection in sister-chromatid recombination (SCR) as the major repair mechanism of spontaneous DSBs, we used a circular minichromosome system for the repair of replication-born DSBs by SCR in yeast. We provide evidence that MRX, particularly its Mre11 nuclease activity, and Sae2 are required for SCR-mediated repair of DSBs. The phenotype of nuclease-deficient MRX mutants is suppressed by ablation of Yku70 or overexpression of Exo1, suggesting a competition between NHEJ and resection factors for DNA ends arising during replication. In addition, we observe partially redundant roles for Sgs1 and Exo1 in SCR, with a more prominent role for Sgs1. Using human U2OS cells, we also show that the competitive nature of these reactions is likely evolutionarily conserved. These results further our understanding of the role of DNA resection in repair of replication-born DSBs revealing unanticipated differences between these events and repair of enzymatically induced DSBs.
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Affiliation(s)
- Sandra Muñoz-Galván
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla-CSIC, Av. Américo Vespucio s/n, 41092 Seville, Spain
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