1
|
Zeng T, Ni Y, Li J, Chen H, Lu Q, Jiang M, Xu L, Liu C, Xiao P. Comprehensive analysis of the mitochondrial genome of Rehmannia glutinosa: insights into repeat-mediated recombinations and RNA editing-induced stop codon acquisition. FRONTIERS IN PLANT SCIENCE 2024; 15:1326387. [PMID: 38807783 PMCID: PMC11130359 DOI: 10.3389/fpls.2024.1326387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 04/24/2024] [Indexed: 05/30/2024]
Abstract
Rehmannia glutinosa is an economically significant medicinal plant. Yet, the structure and sequence of its mitochondrial genome has not been published, which plays a crucial role in evolutionary analysis and regulating respiratory-related macromolecule synthesis. In this study, the R. glutinosa mitogenome was sequenced employing a combination of Illumina short reads and Nanopore long reads, with subsequent assembly using a hybrid strategy. We found that the predominant configuration of the R. glutinosa mitogenome comprises two circular chromosomes. The primary structure of the mitogenome encompasses two mitochondrial chromosomes corresponding to the two major configurations, Mac1-1 and Mac1-2. The R. glutinosa mitogenome encoded an angiosperm-typical set of 24 core genes, nine variable genes, three rRNA genes, and 15 tRNA genes. A phylogenetic analysis using the 16 shared protein-coding genes (PCG) yielded a tree consistent with the phylogeny of Lamiales species and two outgroup taxa. Mapping RNA-seq data to the coding sequences (CDS) of the PCGs revealed 507 C-to-U RNA editing sites across 31 PCGs of the R. glutinosa mitogenome. Furthermore, one start codon (nad4L) and two stop codons (rpl10 and atp6) were identified as products of RNA editing events in the R. glutinosa mitogenome.
Collapse
Affiliation(s)
- Tiexin Zeng
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yang Ni
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Jingling Li
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Haimei Chen
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Qianqi Lu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Mei Jiang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Lijia Xu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Chang Liu
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Peigen Xiao
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| |
Collapse
|
2
|
Cook D, Kozmin SG, Yeh E, Petes TD, Bloom K. Dicentric chromosomes are resolved through breakage and repair at their centromeres. Chromosoma 2024; 133:117-134. [PMID: 38165460 PMCID: PMC11180013 DOI: 10.1007/s00412-023-00814-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 11/11/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
Chromosomes with two centromeres provide a unique opportunity to study chromosome breakage and DNA repair using completely endogenous cellular machinery. Using a conditional transcriptional promoter to control the second centromere, we are able to activate the dicentric chromosome and follow the appearance of DNA repair products. We find that the rate of appearance of DNA repair products resulting from homology-based mechanisms exceeds the expected rate based on their limited centromere homology (340 bp) and distance from one another (up to 46.3 kb). In order to identify whether DNA breaks originate in the centromere, we introduced 12 single-nucleotide polymorphisms (SNPs) into one of the centromeres. Analysis of the distribution of SNPs in the recombinant centromeres reveals that recombination was initiated with about equal frequency within the conserved centromere DNA elements CDEII and CDEIII of the two centromeres. The conversion tracts range from about 50 bp to the full length of the homology between the two centromeres (340 bp). Breakage and repair events within and between the centromeres can account for the efficiency and distribution of DNA repair products. We propose that in addition to providing a site for kinetochore assembly, the centromere may be a point of stress relief in the face of genomic perturbations.
Collapse
Affiliation(s)
- Diana Cook
- Department of Biology, University of North Carolina Chapel Hill, Chapel Hill, NC, 27599-3280, USA
| | - Stanislav G Kozmin
- Department of Molecular Genetics & Microbiology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Elaine Yeh
- Department of Biology, University of North Carolina Chapel Hill, Chapel Hill, NC, 27599-3280, USA
| | - Thomas D Petes
- Department of Molecular Genetics & Microbiology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Kerry Bloom
- Department of Biology, University of North Carolina Chapel Hill, Chapel Hill, NC, 27599-3280, USA.
| |
Collapse
|
3
|
Di Tommaso E, Giunta S. Dynamic interplay between human alpha-satellite DNA structure and centromere functions. Semin Cell Dev Biol 2024; 156:130-140. [PMID: 37926668 DOI: 10.1016/j.semcdb.2023.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/04/2023] [Accepted: 10/10/2023] [Indexed: 11/07/2023]
Abstract
Maintenance of genome stability relies on functional centromeres for correct chromosome segregation and faithful inheritance of the genetic information. The human centromere is the primary constriction within mitotic chromosomes made up of repetitive alpha-satellite DNA hierarchically organized in megabase-long arrays of near-identical higher order repeats (HORs). Centromeres are epigenetically specified by the presence of the centromere-specific histone H3 variant, CENP-A, which enables the assembly of the kinetochore for microtubule attachment. Notably, centromeric DNA is faithfully inherited as intact haplotypes from the parents to the offspring without intervening recombination, yet, outside of meiosis, centromeres are akin to common fragile sites (CFSs), manifesting crossing-overs and ongoing sequence instability. Consequences of DNA changes within the centromere are just starting to emerge, with unclear effects on intra- and inter-generational inheritance driven by centromere's essential role in kinetochore assembly. Here, we review evidence of meiotic selection operating to mitigate centromere drive, as well as recent reports on centromere damage, recombination and repair during the mitotic cell division. We propose an antagonistic pleiotropy interpretation to reconcile centromere DNA instability as both driver of aneuploidy that underlies degenerative diseases, while also potentially necessary for the maintenance of homogenized HORs for centromere function. We attempt to provide a framework for this conceptual leap taking into consideration the structural interface of centromere-kinetochore interaction and present case scenarios for its malfunctioning. Finally, we offer an integrated working model to connect DNA instability, chromatin, and structural changes with functional consequences on chromosome integrity.
Collapse
Affiliation(s)
- Elena Di Tommaso
- Laboratory of Genome Evolution, Department of Biology & Biotechnology Charles Darwin, Sapienza University of Rome, Rome 00185, Italy
| | - Simona Giunta
- Laboratory of Genome Evolution, Department of Biology & Biotechnology Charles Darwin, Sapienza University of Rome, Rome 00185, Italy.
| |
Collapse
|
4
|
Xu R, Pan Z, Nakagawa T. Gross Chromosomal Rearrangement at Centromeres. Biomolecules 2023; 14:28. [PMID: 38254628 PMCID: PMC10813616 DOI: 10.3390/biom14010028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
Centromeres play essential roles in the faithful segregation of chromosomes. CENP-A, the centromere-specific histone H3 variant, and heterochromatin characterized by di- or tri-methylation of histone H3 9th lysine (H3K9) are the hallmarks of centromere chromatin. Contrary to the epigenetic marks, DNA sequences underlying the centromere region of chromosomes are not well conserved through evolution. However, centromeres consist of repetitive sequences in many eukaryotes, including animals, plants, and a subset of fungi, including fission yeast. Advances in long-read sequencing techniques have uncovered the complete sequence of human centromeres containing more than thousands of alpha satellite repeats and other types of repetitive sequences. Not only tandem but also inverted repeats are present at a centromere. DNA recombination between centromere repeats can result in gross chromosomal rearrangement (GCR), such as translocation and isochromosome formation. CENP-A chromatin and heterochromatin suppress the centromeric GCR. The key player of homologous recombination, Rad51, safeguards centromere integrity through conservative noncrossover recombination between centromere repeats. In contrast to Rad51-dependent recombination, Rad52-mediated single-strand annealing (SSA) and microhomology-mediated end-joining (MMEJ) lead to centromeric GCR. This review summarizes recent findings on the role of centromere and recombination proteins in maintaining centromere integrity and discusses how GCR occurs at centromeres.
Collapse
Affiliation(s)
- Ran Xu
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
- Forefront Research Center, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
| | - Ziyi Pan
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
- Forefront Research Center, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
| | - Takuro Nakagawa
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
- Forefront Research Center, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka 560-0043, Osaka, Japan
| |
Collapse
|
5
|
Activation of homologous recombination in G1 preserves centromeric integrity. Nature 2021; 600:748-753. [PMID: 34853474 DOI: 10.1038/s41586-021-04200-z] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 11/02/2021] [Indexed: 01/01/2023]
Abstract
Centromeric integrity is key for proper chromosome segregation during cell division1. Centromeres have unique chromatin features that are essential for centromere maintenance2. Although they are intrinsically fragile and represent hotspots for chromosomal rearrangements3, little is known about how centromere integrity in response to DNA damage is preserved. DNA repair by homologous recombination requires the presence of the sister chromatid and is suppressed in the G1 phase of the cell cycle4. Here we demonstrate that DNA breaks that occur at centromeres in G1 recruit the homologous recombination machinery, despite the absence of a sister chromatid. Mechanistically, we show that the centromere-specific histone H3 variant CENP-A and its chaperone HJURP, together with dimethylation of lysine 4 in histone 3 (H3K4me2), enable a succession of events leading to the licensing of homologous recombination in G1. H3K4me2 promotes DNA-end resection by allowing DNA damage-induced centromeric transcription and increased formation of DNA-RNA hybrids. CENP-A and HJURP interact with the deubiquitinase USP11, enabling formation of the RAD51-BRCA1-BRCA2 complex5 and rendering the centromeres accessible to RAD51 recruitment and homologous recombination in G1. Finally, we show that inhibition of homologous recombination in G1 leads to centromeric instability and chromosomal translocations. Our results support a model in which licensing of homologous recombination at centromeric breaks occurs throughout the cell cycle to prevent the activation of mutagenic DNA repair pathways and preserve centromeric integrity.
Collapse
|
6
|
Garrido-Ramos MA. The Genomics of Plant Satellite DNA. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2021; 60:103-143. [PMID: 34386874 DOI: 10.1007/978-3-030-74889-0_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The twenty-first century began with a certain indifference to the research of satellite DNA (satDNA). Neither genome sequencing projects were able to accurately encompass the study of satDNA nor classic methodologies were able to go further in undertaking a better comprehensive study of the whole set of satDNA sequences of a genome. Nonetheless, knowledge of satDNA has progressively advanced during this century with the advent of new analytical techniques. The enormous advantages that genome-wide approaches have brought to its analysis have now stimulated a renewed interest in the study of satDNA. At this point, we can look back and try to assess more accurately many of the key questions that were left unsolved in the past about this enigmatic and important component of the genome. I review here the understanding gathered on plant satDNAs over the last few decades with an eye on the near future.
Collapse
|
7
|
The Curious Case of Nonrepetitive Centromeric DNA Sequences in Candida auris and Related Species. mBio 2021; 12:e0147621. [PMID: 34340554 PMCID: PMC8406187 DOI: 10.1128/mbio.01476-21] [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] [Indexed: 11/22/2022] Open
Abstract
2009 saw the first description of Candida auris, a yeast pathogen of humans. C. auris has since grown into a global problem in intensive care settings, where it causes systemic infections in patients with underlying health issues. Recent whole-genome sequencing has discerned five C. auris clades with distinct phenotypic features which display genomic divergence on a DNA sequence and a chromosome structure level. In the absence of sexual reproduction in C. auris, the mechanism(s) behind the rapid genomic evolution of this emerging killer yeast has remained obscure. Yet, one important bit of information about chromosome organization was missing, the identification of the centromeres. In a recent study, Sanyal and coworkers (A. Narayanan, R. N. Vadnala, P. Ganguly, P. Selvakumar, et al., mBio 12:e00905-21, 2021, https://doi.org/10.1128/mBio.00905-21) filled this knowledge gap by mapping the centromeres in C. auris and its close relatives. This represents a major advance in the chromosome biology of the Candida/Clavispora clade.
Collapse
|
8
|
Boštjančić LL, Bonassin L, Anušić L, Lovrenčić L, Besendorfer V, Maguire I, Grandjean F, Austin CM, Greve C, Hamadou AB, Mlinarec J. The Pontastacus leptodactylus (Astacidae) Repeatome Provides Insight Into Genome Evolution and Reveals Remarkable Diversity of Satellite DNA. Front Genet 2021; 11:611745. [PMID: 33552130 PMCID: PMC7859515 DOI: 10.3389/fgene.2020.611745] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/21/2020] [Indexed: 12/14/2022] Open
Abstract
Pontastacus leptodactylus is a native European crayfish species found in both freshwater and brackish environments. It has commercial importance for fisheries and aquaculture industries. Up till now, most studies concerning P. leptodactylus have focused onto gaining knowledge about its phylogeny and population genetics. However, little is known about the chromosomal evolution and genome organization of this species. Therefore, we performed clustering analysis of a low coverage genomic dataset to identify and characterize repetitive DNA in the P. leptodactylus genome. In addition, the karyogram of P. leptodactylus (2n = 180) is presented here for the first time consisting of 75 metacentric, 14 submetacentric, and a submetacentric/metacentric heteromorphic chromosome pair. We determined the genome size to be at ~18.7 gigabase pairs. Repetitive DNA represents about 54.85% of the genome. Satellite DNA repeats are the most abundant type of repetitive DNA, making up to ~28% of the total amount of repetitive elements, followed by the Ty3/Gypsy retroelements (~15%). Our study established a surprisingly high diversity of satellite repeats in P. leptodactylus. The genome of P. leptodactylus is by far the most satellite-rich genome discovered to date with 258 satellite families described. Of the five mapped satellite DNA families on chromosomes, PlSAT3-411 co-localizes with the AT-rich DAPI positive probable (peri)centromeric heterochromatin on all chromosomes, while PlSAT14-79 co-localizes with the AT-rich DAPI positive (peri)centromeric heterochromatin on one chromosome and is also located subterminally and intercalary on some chromosomes. PlSAT1-21 is located intercalary in the vicinity of the (peri)centromeric heterochromatin on some chromosomes, while PlSAT6-70 and PlSAT7-134 are located intercalary on some P. leptodactylus chromosomes. The FISH results reveal amplification of interstitial telomeric repeats (ITRs) in P. leptodactylus. The prevalence of repetitive elements, especially the satellite DNA repeats, may have provided a driving force for the evolution of the P. leptodactylus genome.
Collapse
Affiliation(s)
| | - Lena Bonassin
- Division of Molecular Biology, Department of Biology, University of Zagreb, Zagreb, Croatia
| | - Lucija Anušić
- Division of Molecular Biology, Department of Biology, University of Zagreb, Zagreb, Croatia
| | - Leona Lovrenčić
- Division of Zoology, Department of Biology, University of Zagreb, Zagreb, Croatia
| | - Višnja Besendorfer
- Division of Molecular Biology, Department of Biology, University of Zagreb, Zagreb, Croatia
| | - Ivana Maguire
- Division of Zoology, Department of Biology, University of Zagreb, Zagreb, Croatia
| | - Frederic Grandjean
- Laboratoire Ecologie Biologie des Interactions-UMR CNRS 7267, University of Poitiers, Poitiers, France
| | - Christopher M. Austin
- Centre of Integrative Ecology, School of Life and Environmental Sciences Deakin University, Geelong, VIC, Australia
| | - Carola Greve
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt, Germany
| | - Alexander Ben Hamadou
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt, Germany
| | - Jelena Mlinarec
- Division of Molecular Biology, Department of Biology, University of Zagreb, Zagreb, Croatia
| |
Collapse
|
9
|
Ávila Robledillo L, Neumann P, Koblížková A, Novák P, Vrbová I, Macas J. Extraordinary Sequence Diversity and Promiscuity of Centromeric Satellites in the Legume Tribe Fabeae. Mol Biol Evol 2020; 37:2341-2356. [PMID: 32259249 PMCID: PMC7403623 DOI: 10.1093/molbev/msaa090] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Satellite repeats are major sequence constituents of centromeres in many plant and animal species. Within a species, a single family of satellite sequences typically occupies centromeres of all chromosomes and is absent from other parts of the genome. Due to their common origin, sequence similarities exist among the centromere-specific satellites in related species. Here, we report a remarkably different pattern of centromere evolution in the plant tribe Fabeae, which includes genera Pisum, Lathyrus, Vicia, and Lens. By immunoprecipitation of centromeric chromatin with CENH3 antibodies, we identified and characterized a large and diverse set of 64 families of centromeric satellites in 14 species. These families differed in their nucleotide sequence, monomer length (33-2,979 bp), and abundance in individual species. Most families were species-specific, and most species possessed multiple (2-12) satellites in their centromeres. Some of the repeats that were shared by several species exhibited promiscuous patterns of centromere association, being located within CENH3 chromatin in some species, but apart from the centromeres in others. Moreover, FISH experiments revealed that the same family could assume centromeric and noncentromeric positions even within a single species. Taken together, these findings suggest that Fabeae centromeres are not shaped by the coevolution of a single centromeric satellite with its interacting CENH3 proteins, as proposed by the centromere drive model. This conclusion is also supported by the absence of pervasive adaptive evolution of CENH3 sequences retrieved from Fabeae species.
Collapse
Affiliation(s)
- Laura Ávila Robledillo
- Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Pavel Neumann
- Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Andrea Koblížková
- Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Petr Novák
- Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Iva Vrbová
- Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Jiří Macas
- Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| |
Collapse
|
10
|
Damasceno JD, Reis-Cunha J, Crouch K, Beraldi D, Lapsley C, Tosi LRO, Bartholomeu D, McCulloch R. Conditional knockout of RAD51-related genes in Leishmania major reveals a critical role for homologous recombination during genome replication. PLoS Genet 2020; 16:e1008828. [PMID: 32609721 PMCID: PMC7360064 DOI: 10.1371/journal.pgen.1008828] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 07/14/2020] [Accepted: 05/05/2020] [Indexed: 12/12/2022] Open
Abstract
Homologous recombination (HR) has an intimate relationship with genome replication, both during repair of DNA lesions that might prevent DNA synthesis and in tackling stalls to the replication fork. Recent studies led us to ask if HR might have a more central role in replicating the genome of Leishmania, a eukaryotic parasite. Conflicting evidence has emerged regarding whether or not HR genes are essential, and genome-wide mapping has provided evidence for an unorthodox organisation of DNA replication initiation sites, termed origins. To answer this question, we have employed a combined CRISPR/Cas9 and DiCre approach to rapidly generate and assess the effect of conditional ablation of RAD51 and three RAD51-related proteins in Leishmania major. Using this approach, we demonstrate that loss of any of these HR factors is not immediately lethal but in each case growth slows with time and leads to DNA damage and accumulation of cells with aberrant DNA content. Despite these similarities, we show that only loss of RAD51 or RAD51-3 impairs DNA synthesis and causes elevated levels of genome-wide mutation. Furthermore, we show that these two HR factors act in distinct ways, since ablation of RAD51, but not RAD51-3, has a profound effect on DNA replication, causing loss of initiation at the major origins and increased DNA synthesis at subtelomeres. Our work clarifies questions regarding the importance of HR to survival of Leishmania and reveals an unanticipated, central role for RAD51 in the programme of genome replication in a microbial eukaryote.
Collapse
Affiliation(s)
- Jeziel D. Damasceno
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, United Kingdom
- * E-mail: (JDD); (RM)
| | - João Reis-Cunha
- Laboratório de Imunologia e Genômica de Parasitos, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brasil
| | - Kathryn Crouch
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, United Kingdom
| | - Dario Beraldi
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, United Kingdom
| | - Craig Lapsley
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, United Kingdom
| | - Luiz R. O. Tosi
- Department of Cell and Molecular Biology, Ribeirão Preto Medical School, University of São Paulo; Ribeirão Preto, SP, Brazil
| | - Daniella Bartholomeu
- Laboratório de Imunologia e Genômica de Parasitos, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brasil
| | - Richard McCulloch
- The Wellcome Centre for Integrative Parasitology, University of Glasgow, Institute of Infection, Immunity and Inflammation, Sir Graeme Davies Building, 120 University Place, Glasgow, United Kingdom
- * E-mail: (JDD); (RM)
| |
Collapse
|
11
|
Puppo IL, Saifitdinova AF, Tonyan ZN. The Role of Satellite DNA in Causing Structural Rearrangements in Human Karyotype. RUSS J GENET+ 2020. [DOI: 10.1134/s1022795419080155] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
12
|
Lawrimore CJ, Bloom K. Common Features of the Pericentromere and Nucleolus. Genes (Basel) 2019; 10:E1029. [PMID: 31835574 PMCID: PMC6947172 DOI: 10.3390/genes10121029] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/05/2019] [Accepted: 12/07/2019] [Indexed: 12/20/2022] Open
Abstract
Both the pericentromere and the nucleolus have unique characteristics that distinguish them amongst the rest of genome. Looping of pericentromeric DNA, due to structural maintenance of chromosome (SMC) proteins condensin and cohesin, drives its ability to maintain tension during metaphase. Similar loops are formed via condensin and cohesin in nucleolar ribosomal DNA (rDNA). Condensin and cohesin are also concentrated in transfer RNA (tRNA) genes, genes which may be located within the pericentromere as well as tethered to the nucleolus. Replication fork stalling, as well as downstream consequences such as genomic recombination, are characteristic of both the pericentromere and rDNA. Furthermore, emerging evidence suggests that the pericentromere may function as a liquid-liquid phase separated domain, similar to the nucleolus. We therefore propose that the pericentromere and nucleolus, in part due to their enrichment of SMC proteins and others, contain similar domains that drive important cellular activities such as segregation, stability, and repair.
Collapse
Affiliation(s)
| | - Kerry Bloom
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280, USA;
| |
Collapse
|
13
|
Van-Lume B, Mata-Sucre Y, Báez M, Ribeiro T, Huettel B, Gagnon E, Leitch IJ, Pedrosa-Harand A, Lewis GP, Souza G. Evolutionary convergence or homology? Comparative cytogenomics of Caesalpinia group species (Leguminosae) reveals diversification in the pericentromeric heterochromatic composition. PLANTA 2019; 250:2173-2186. [PMID: 31696317 DOI: 10.1007/s00425-019-03287-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 09/25/2019] [Indexed: 05/02/2023]
Abstract
We demonstrated by cytogenomic analysis that the proximal heterochromatin of the Northeast Brazilian species of Caesalpinia group is enriched with phylogenetically conserved Ty3/Gypsy-Tekay RT, but diverge in the presence of Ty3/Gypsy-Athila RT and satDNA. The Caesalpinia Group includes 225 species and 27 monophyletic genera of which four occur in Northeastern Brazil: Erythrostemon (1 sp.), Cenostigma (7 spp.), Libidibia (1 sp.), and Paubrasilia (1 sp.). The last three genera are placed in different clades in the Caesalpinia Group phylogeny, and yet they are characterized by having a numerically stable karyotype 2n = 24 (16 M+8A) and GC-rich heterochromatic bands (chromomycin A3 positive/CMA+ bands) in the proximal chromosome regions. To characterize the composition of their heterochromatin and test for the homology of these chromosomal regions, genomic DNA was extracted from Cenostigma microphyllum, Libidibia ferrea, and Paubrasilia echinata, and sequenced at low coverage using the Illumina platform. The genomic repetitive fractions were characterized using a Galaxy/RepeatExplorer-Elixir platform. The most abundant elements of each genome were chromosomally located by fluorescent in situ hybridization (FISH) and compared to the CMA+ heterochromatin distribution. The repetitive fraction of the genomes of C. microphyllum, L. ferrea, and P. echinata were estimated to be 41.70%, 38.44%, and 72.51%, respectively. Ty3/Gypsy retrotransposons (RT), specifically the Tekay lineage, were the most abundant repeats in each of the three genomes. FISH mapping revealed species-specific patterns for the Tekay elements in the proximal regions of the chromosomes, co-localized with CMA+ bands. Other species-specific patterns were observed, e.g., for the Ty3/Gypsy RT Athila elements which were found in all the proximal heterochromatin of L. ferrea or restricted to the acrocentric chromosomes of C. microphyllum. This Athila labeling co-localized with satellite DNAs (satDNAs). Although the Caesalpinia Group diverged around 55 Mya, our results suggest an ancestral colonization of Tekay RT in the proximal heterochromatin. Thus, the present-day composition of the pericentromeric heterochromatin in these Northeast Brazilian species is a combination of the maintenance of an ancestral Tekay distribution with a species-specific accumulation of other repeats.
Collapse
Affiliation(s)
- Brena Van-Lume
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitária, Recife, PE, 50670-420, Brazil
| | - Yennifer Mata-Sucre
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitária, Recife, PE, 50670-420, Brazil
| | - Mariana Báez
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitária, Recife, PE, 50670-420, Brazil
| | - Tiago Ribeiro
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitária, Recife, PE, 50670-420, Brazil
- Department of Botany and Ecology, Institute of Biosciences, Federal University of Mato Grosso, Av. Fernando Correa da Costa, 2.367, Boa Esperança, Cuiabá, MT, 78060-900, Brazil
| | | | - Edeline Gagnon
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, EH3 5NZ, UK
| | - Ilia J Leitch
- Department of Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
| | - Andrea Pedrosa-Harand
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitária, Recife, PE, 50670-420, Brazil
| | - Gwilym P Lewis
- Department of Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK
| | - Gustavo Souza
- Laboratory of Plant Cytogenetics and Evolution, Department of Botany, Federal University of Pernambuco, Rua Nelson Chaves S/N, Cidade Universitária, Recife, PE, 50670-420, Brazil.
| |
Collapse
|
14
|
Lawrimore J, Bloom K. The regulation of chromosome segregation via centromere loops. Crit Rev Biochem Mol Biol 2019; 54:352-370. [PMID: 31573359 PMCID: PMC6856439 DOI: 10.1080/10409238.2019.1670130] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/02/2019] [Accepted: 09/17/2019] [Indexed: 12/14/2022]
Abstract
Biophysical studies of the yeast centromere have shown that the organization of the centromeric chromatin plays a crucial role in maintaining proper tension between sister kinetochores during mitosis. While centromeric chromatin has traditionally been considered a simple spring, recent work reveals the centromere as a multifaceted, tunable shock absorber. Centromeres can differ from other regions of the genome in their heterochromatin state, supercoiling state, and enrichment of structural maintenance of chromosomes (SMC) protein complexes. Each of these differences can be utilized to alter the effective stiffness of centromeric chromatin. In budding yeast, the SMC protein complexes condensin and cohesin stiffen chromatin by forming and cross-linking chromatin loops, respectively, into a fibrous structure resembling a bottlebrush. The high density of the loops compacts chromatin while spatially isolating the tension from spindle pulling forces to a subset of the chromatin. Paradoxically, the molecular crowding of chromatin via cohesin and condensin also causes an outward/poleward force. The structure allows the centromere to act as a shock absorber that buffers the variable forces generated by dynamic spindle microtubules. Based on the distribution of SMCs from bacteria to human and the conserved distance between sister kinetochores in a wide variety of organisms (0.4 to 1 micron), we propose that the bottlebrush mechanism is the foundational principle for centromere function in eukaryotes.
Collapse
Affiliation(s)
- Josh Lawrimore
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kerry Bloom
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
15
|
Black EM, Giunta S. Repetitive Fragile Sites: Centromere Satellite DNA As a Source of Genome Instability in Human Diseases. Genes (Basel) 2018; 9:E615. [PMID: 30544645 PMCID: PMC6315641 DOI: 10.3390/genes9120615] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 12/03/2018] [Accepted: 12/03/2018] [Indexed: 12/31/2022] Open
Abstract
Maintenance of an intact genome is essential for cellular and organismal homeostasis. The centromere is a specialized chromosomal locus required for faithful genome inheritance at each round of cell division. Human centromeres are composed of large tandem arrays of repetitive alpha-satellite DNA, which are often sites of aberrant rearrangements that may lead to chromosome fusions and genetic abnormalities. While the centromere has an essential role in chromosome segregation during mitosis, the long and repetitive nature of the highly identical repeats has greatly hindered in-depth genetic studies, and complete annotation of all human centromeres is still lacking. Here, we review our current understanding of human centromere genetics and epigenetics as well as recent investigations into the role of centromere DNA in disease, with a special focus on cancer, aging, and human immunodeficiency⁻centromeric instability⁻facial anomalies (ICF) syndrome. We also highlight the causes and consequences of genomic instability at these large repetitive arrays and describe the possible sources of centromere fragility. The novel connection between alpha-satellite DNA instability and human pathological conditions emphasizes the importance of obtaining a truly complete human genome assembly and accelerating our understanding of centromere repeats' role in physiology and beyond.
Collapse
Affiliation(s)
- Elizabeth M Black
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| | - Simona Giunta
- Laboratory of Chromosome and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
| |
Collapse
|
16
|
Barra V, Fachinetti D. The dark side of centromeres: types, causes and consequences of structural abnormalities implicating centromeric DNA. Nat Commun 2018; 9:4340. [PMID: 30337534 PMCID: PMC6194107 DOI: 10.1038/s41467-018-06545-y] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 09/06/2018] [Indexed: 12/18/2022] Open
Abstract
Centromeres are the chromosomal domains required to ensure faithful transmission of the genome during cell division. They have a central role in preventing aneuploidy, by orchestrating the assembly of several components required for chromosome separation. However, centromeres also adopt a complex structure that makes them susceptible to being sites of chromosome rearrangements. Therefore, preservation of centromere integrity is a difficult, but important task for the cell. In this review, we discuss how centromeres could potentially be a source of genome instability and how centromere aberrations and rearrangements are linked with human diseases such as cancer.
Collapse
Affiliation(s)
- V Barra
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm, F-75005, Paris, France
| | - D Fachinetti
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm, F-75005, Paris, France.
| |
Collapse
|
17
|
Haenel Q, Laurentino TG, Roesti M, Berner D. Meta-analysis of chromosome-scale crossover rate variation in eukaryotes and its significance to evolutionary genomics. Mol Ecol 2018; 27:2477-2497. [PMID: 29676042 DOI: 10.1111/mec.14699] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 03/23/2018] [Accepted: 03/26/2018] [Indexed: 01/02/2023]
Abstract
Understanding the distribution of crossovers along chromosomes is crucial to evolutionary genomics because the crossover rate determines how strongly a genome region is influenced by natural selection on linked sites. Nevertheless, generalities in the chromosome-scale distribution of crossovers have not been investigated formally. We fill this gap by synthesizing joint information on genetic and physical maps across 62 animal, plant and fungal species. Our quantitative analysis reveals a strong and taxonomically widespread reduction of the crossover rate in the centre of chromosomes relative to their peripheries. We demonstrate that this pattern is poorly explained by the position of the centromere, but find that the magnitude of the relative reduction in the crossover rate in chromosome centres increases with chromosome length. That is, long chromosomes often display a dramatically low crossover rate in their centre, whereas short chromosomes exhibit a relatively homogeneous crossover rate. This observation is compatible with a model in which crossover is initiated from the chromosome tips, an idea with preliminary support from mechanistic investigations of meiotic recombination. Consequently, we show that organisms achieve a higher genome-wide crossover rate by evolving smaller chromosomes. Summarizing theory and providing empirical examples, we finally highlight that taxonomically widespread and systematic heterogeneity in crossover rate along chromosomes generates predictable broad-scale trends in genetic diversity and population differentiation by modifying the impact of natural selection among regions within a genome. We conclude by emphasizing that chromosome-scale heterogeneity in crossover rate should urgently be incorporated into analytical tools in evolutionary genomics, and in the interpretation of resulting patterns.
Collapse
Affiliation(s)
- Quiterie Haenel
- Zoological Institute, University of Basel, Basel, Switzerland
| | | | - Marius Roesti
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Daniel Berner
- Zoological Institute, University of Basel, Basel, Switzerland
| |
Collapse
|
18
|
Ávila Robledillo L, Koblížková A, Novák P, Böttinger K, Vrbová I, Neumann P, Schubert I, Macas J. Satellite DNA in Vicia faba is characterized by remarkable diversity in its sequence composition, association with centromeres, and replication timing. Sci Rep 2018; 8:5838. [PMID: 29643436 PMCID: PMC5895790 DOI: 10.1038/s41598-018-24196-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 03/28/2018] [Indexed: 11/17/2022] Open
Abstract
Satellite DNA, a class of repetitive sequences forming long arrays of tandemly repeated units, represents substantial portions of many plant genomes yet remains poorly characterized due to various methodological obstacles. Here we show that the genome of the field bean (Vicia faba, 2n = 12), a long-established model for cytogenetic studies in plants, contains a diverse set of satellite repeats, most of which remained concealed until their present investigation. Using next-generation sequencing combined with novel bioinformatics tools, we reconstructed consensus sequences of 23 novel satellite repeats representing 0.008–2.700% of the genome and mapped their distribution on chromosomes. We found that in addition to typical satellites with monomers hundreds of nucleotides long, V. faba contains a large number of satellite repeats with unusually long monomers (687–2033 bp), which are predominantly localized in pericentromeric regions. Using chromatin immunoprecipitation with CenH3 antibody, we revealed an extraordinary diversity of centromeric satellites, consisting of seven repeats with chromosome-specific distribution. We also found that in spite of their different nucleotide sequences, all centromeric repeats are replicated during mid-S phase, while most other satellites are replicated in the first part of late S phase, followed by a single family of FokI repeats representing the latest replicating chromatin.
Collapse
Affiliation(s)
- Laura Ávila Robledillo
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, 37005, Czech Republic.,University of South Bohemia, Faculty of Science, České Budějovice, 37005, Czech Republic
| | - Andrea Koblížková
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, 37005, Czech Republic
| | - Petr Novák
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, 37005, Czech Republic
| | - Katharina Böttinger
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, 37005, Czech Republic.,University of South Bohemia, Faculty of Science, České Budějovice, 37005, Czech Republic
| | - Iva Vrbová
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, 37005, Czech Republic
| | - Pavel Neumann
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, 37005, Czech Republic
| | - Ingo Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), 06466, Gatersleben, Stadt Seeland, Germany
| | - Jiří Macas
- Biology Centre of the Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, 37005, Czech Republic.
| |
Collapse
|
19
|
Integrity of the human centromere DNA repeats is protected by CENP-A, CENP-C, and CENP-T. Proc Natl Acad Sci U S A 2017; 114:1928-1933. [PMID: 28167779 DOI: 10.1073/pnas.1615133114] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Centromeres are highly specialized chromatin domains that enable chromosome segregation and orchestrate faithful cell division. Human centromeres are composed of tandem arrays of α-satellite DNA, which spans up to several megabases. Little is known about the mechanisms that maintain integrity of the long arrays of α-satellite DNA repeats. Here, we monitored centromeric repeat stability in human cells using chromosome-orientation fluorescent in situ hybridization (CO-FISH). This assay detected aberrant centromeric CO-FISH patterns consistent with sister chromatid exchange at the frequency of 5% in primary tissue culture cells, whereas higher levels were seen in several cancer cell lines and during replicative senescence. To understand the mechanism(s) that maintains centromere integrity, we examined the contribution of the centromere-specific histone variant CENP-A and members of the constitutive centromere-associated network (CCAN), CENP-C, CENP-T, and CENP-W. Depletion of CENP-A and CCAN proteins led to an increase in centromere aberrations, whereas enhancing chromosome missegregation by alternative methods did not, suggesting that CENP-A and CCAN proteins help maintain centromere integrity independently of their role in chromosome segregation. Furthermore, superresolution imaging of centromeric CO-FISH using structured illumination microscopy implied that CENP-A protects α-satellite repeats from extensive rearrangements. Our study points toward the presence of a centromere-specific mechanism that actively maintains α-satellite repeat integrity during human cell proliferation.
Collapse
|
20
|
Forsburg SL, Shen KF. Centromere Stability: The Replication Connection. Genes (Basel) 2017; 8:genes8010037. [PMID: 28106789 PMCID: PMC5295031 DOI: 10.3390/genes8010037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 01/10/2017] [Accepted: 01/12/2017] [Indexed: 11/16/2022] Open
Abstract
The fission yeast centromere, which is similar to metazoan centromeres, contains highly repetitive pericentromere sequences that are assembled into heterochromatin. This is required for the recruitment of cohesin and proper chromosome segregation. Surprisingly, the pericentromere replicates early in the S phase. Loss of heterochromatin causes this domain to become very sensitive to replication fork defects, leading to gross chromosome rearrangements. This review examines the interplay between components of DNA replication, heterochromatin assembly, and cohesin dynamics that ensures maintenance of genome stability and proper chromosome segregation.
Collapse
Affiliation(s)
- Susan L Forsburg
- Program in Molecular & Computational Biology, University of Southern California, Los Angeles, CA 90089-2910, USA.
| | - Kuo-Fang Shen
- Program in Molecular & Computational Biology, University of Southern California, Los Angeles, CA 90089-2910, USA.
| |
Collapse
|
21
|
Bloom K, Costanzo V. Centromere Structure and Function. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2017; 56:515-539. [PMID: 28840251 DOI: 10.1007/978-3-319-58592-5_21] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The centromere is the genetic locus that specifies the site of kinetochore assembly, where the chromosome will attach to the kinetochore microtubule. The pericentromere is the physical region responsible for the geometry of bi-oriented sister kinetochores in metaphase. In budding yeast the 125 bp point centromere is sufficient to specify kinetochore assembly. The flanking region is enriched (3X) in cohesin and condensin relative to the remaining chromosome arms. The enrichment spans about 30-50 kb around each centromere. We refer to the flanking chromatin as the pericentromere in yeast. In mammals, a 5-10 Mb region dictates where the kinetochore is built. The kinetochore interacts with a very small fraction of DNA on the surface of the centromeric region. The remainder of the centromere lies between the sister kinetochores. This is typically called centromere chromatin. The chromatin sites that directly interface to microtubules cannot be identified due to the repeated sequence within the mammalian centromere. However in both yeast and mammals, the total amount of DNA between the sites of microtubule attachment in metaphase is highly conserved. In yeast the 16 chromosomes are clustered into a 250 nm diameter region, and 800 kb (16 × 50 kb) or ~1 Mb of DNA lies between sister kinetochores. In mammals, 5-10 Mb lies between sister kinetochores. In both organisms the sister kinetochores are separated by about 1 μm. Thus, centromeres of different organisms differ in how they specify kinetochore assembly, but there may be important centromere chromatin functions that are conserved throughout phylogeny. Recently, centromeric chromatin has been reconstituted in vitro using alpha satellite DNA revealing unexpected features of centromeric DNA organization, replication, and response to stress. We will focus on the conserved features of centromere in this review.
Collapse
Affiliation(s)
- Kerry Bloom
- Department of Biology, University of North Carolina at Chapel Hill, 623 Fordham Hall CB#3280, Chapel Hill, NC, 27599-3280, USA.
| | - Vincenzo Costanzo
- DNA Metabolism Laboratory, IFOM, The FIRC Institute of Molecular Oncology, Vai Adamello 16, 21139, Milan, Italy
| |
Collapse
|
22
|
Dumont M, Fachinetti D. DNA Sequences in Centromere Formation and Function. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2017; 56:305-336. [PMID: 28840243 DOI: 10.1007/978-3-319-58592-5_13] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Faithful chromosome segregation during cell division depends on the centromere, a complex DNA/protein structure that links chromosomes to spindle microtubules. This chromosomal domain has to be marked throughout cell division and its chromosomal localization preserved across cell generations. From fission yeast to human, centromeres are established on a series of repetitive DNA sequences and on specialized centromeric chromatin. This chromatin is enriched with the histone H3 variant, named CENP-A, that was demonstrated to be the epigenetic mark that maintains centromere identity and function indefinitely. Although centromere identity is thought to be exclusively epigenetic, the presence of specific DNA sequences in the majority of eukaryotes and of the centromeric protein CENP-B that binds to these sequences, suggests the existence of a genetic component as well. In this review, we will highlight the importance of centromeric sequences for centromere formation and function, and discuss the centromere DNA sequence/CENP-B paradox.
Collapse
Affiliation(s)
- M Dumont
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm, 75005, Paris, France
| | - D Fachinetti
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm, 75005, Paris, France.
| |
Collapse
|
23
|
Romeo F, Falbo L, Costanzo V. Replication, checkpoint suppression and structure of centromeric DNA. Nucleus 2016; 7:540-546. [PMID: 27893298 DOI: 10.1080/19491034.2016.1255836] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Human centromeres contain large amounts of repetitive DNA sequences known as α satellite DNA, which can be difficult to replicate and whose functional role is unclear. Recently, we have characterized protein composition, structural organization and checkpoint response to stalled replication forks of centromeric chromatin reconstituted in Xenopus laevis egg extract. We showed that centromeric DNA has high affinity for SMC2-4 subunits of condensins and for CENP-A, it is enriched for DNA repair factors and suppresses the ATR checkpoint to ensure its efficient replication. We also showed that centromeric chromatin forms condensins enriched and topologically constrained DNA loops, which likely contribute to the overall structure of the centromere. These findings have important implications on how chromosomes are organized and genome stability is maintained in mammalian cells.
Collapse
Affiliation(s)
- Francesco Romeo
- a DNA metabolism laboratory, IFOM, The FIRC institute for Molecular Oncology , Milan , Italy
| | - Lucia Falbo
- a DNA metabolism laboratory, IFOM, The FIRC institute for Molecular Oncology , Milan , Italy
| | - Vincenzo Costanzo
- a DNA metabolism laboratory, IFOM, The FIRC institute for Molecular Oncology , Milan , Italy
| |
Collapse
|
24
|
Sturmberger L, Chappell T, Geier M, Krainer F, Day KJ, Vide U, Trstenjak S, Schiefer A, Richardson T, Soriaga L, Darnhofer B, Birner-Gruenberger R, Glick BS, Tolstorukov I, Cregg J, Madden K, Glieder A. Refined Pichia pastoris reference genome sequence. J Biotechnol 2016; 235:121-31. [PMID: 27084056 PMCID: PMC5089815 DOI: 10.1016/j.jbiotec.2016.04.023] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/08/2016] [Accepted: 04/11/2016] [Indexed: 11/16/2022]
Abstract
Strains of the species Komagataella phaffii are the most frequently used "Pichia pastoris" strains employed for recombinant protein production as well as studies on peroxisome biogenesis, autophagy and secretory pathway analyses. Genome sequencing of several different P. pastoris strains has provided the foundation for understanding these cellular functions in recent genomics, transcriptomics and proteomics experiments. This experimentation has identified mistakes, gaps and incorrectly annotated open reading frames in the previously published draft genome sequences. Here, a refined reference genome is presented, generated with genome and transcriptome sequencing data from multiple P. pastoris strains. Twelve major sequence gaps from 20 to 6000 base pairs were closed and 5111 out of 5256 putative open reading frames were manually curated and confirmed by RNA-seq and published LC-MS/MS data, including the addition of new open reading frames (ORFs) and a reduction in the number of spliced genes from 797 to 571. One chromosomal fragment of 76kbp between two previous gaps on chromosome 1 and another 134kbp fragment at the end of chromosome 4, as well as several shorter fragments needed re-orientation. In total more than 500 positions in the genome have been corrected. This reference genome is presented with new chromosomal numbering, positioning ribosomal repeats at the distal ends of the four chromosomes, and includes predicted chromosomal centromeres as well as the sequence of two linear cytoplasmic plasmids of 13.1 and 9.5kbp found in some strains of P. pastoris.
Collapse
Affiliation(s)
- Lukas Sturmberger
- Austrian Center of Industrial Biotechnology (ACIB), Petersgasse 14, 8010 Graz, Austria
| | - Thomas Chappell
- BioGrammatics Inc., 2120 Las Palmas Drive, Carlsbad, CA 92011, United States
| | - Martina Geier
- Austrian Center of Industrial Biotechnology (ACIB), Petersgasse 14, 8010 Graz, Austria
| | - Florian Krainer
- Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, 8010 Graz, Austria
| | - Kasey J Day
- Department of Molecular Genetics and Cell Biology, University of Chicago, 920 East 58th St., Chicago, IL 60637, United States
| | - Ursa Vide
- Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, 8010 Graz, Austria
| | - Sara Trstenjak
- Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, 8010 Graz, Austria
| | - Anja Schiefer
- Austrian Center of Industrial Biotechnology (ACIB), Petersgasse 14, 8010 Graz, Austria
| | - Toby Richardson
- Synthetic Genomics, Inc., 11149 North Torrey Pines Rd., La Jolla, CA 92037, United States
| | - Leah Soriaga
- Synthetic Genomics, Inc., 11149 North Torrey Pines Rd., La Jolla, CA 92037, United States
| | - Barbara Darnhofer
- Austrian Center of Industrial Biotechnology (ACIB), Petersgasse 14, 8010 Graz, Austria; Institute of Pathology, Research Unit Functional Proteomics and Metabolic Pathways, Medical University of Graz, Stiftingtalstrasse 24, 8010 Graz, Austria; Omics Center Graz, BioTechMed-Graz, Stiftingtalstrasse 24, 8010 Graz, Austria
| | - Ruth Birner-Gruenberger
- Austrian Center of Industrial Biotechnology (ACIB), Petersgasse 14, 8010 Graz, Austria; Institute of Pathology, Research Unit Functional Proteomics and Metabolic Pathways, Medical University of Graz, Stiftingtalstrasse 24, 8010 Graz, Austria; Omics Center Graz, BioTechMed-Graz, Stiftingtalstrasse 24, 8010 Graz, Austria
| | - Benjamin S Glick
- Department of Molecular Genetics and Cell Biology, University of Chicago, 920 East 58th St., Chicago, IL 60637, United States
| | - Ilya Tolstorukov
- BioGrammatics Inc., 2120 Las Palmas Drive, Carlsbad, CA 92011, United States; Keck Graduate Institute, 535 Watson Drive, Claremont, CA 91711, United States
| | - James Cregg
- BioGrammatics Inc., 2120 Las Palmas Drive, Carlsbad, CA 92011, United States; Keck Graduate Institute, 535 Watson Drive, Claremont, CA 91711, United States
| | - Knut Madden
- BioGrammatics Inc., 2120 Las Palmas Drive, Carlsbad, CA 92011, United States
| | - Anton Glieder
- Austrian Center of Industrial Biotechnology (ACIB), Petersgasse 14, 8010 Graz, Austria; Institute of Molecular Biotechnology, Graz University of Technology, Petersgasse 14, 8010 Graz, Austria; bisy e.U., Wetzawinkel 20, 8200 Hofstaetten/Raab, Austria.
| |
Collapse
|
25
|
Onaka AT, Toyofuku N, Inoue T, Okita AK, Sagawa M, Su J, Shitanda T, Matsuyama R, Zafar F, Takahashi TS, Masukata H, Nakagawa T. Rad51 and Rad54 promote noncrossover recombination between centromere repeats on the same chromatid to prevent isochromosome formation. Nucleic Acids Res 2016; 44:10744-10757. [PMID: 27697832 PMCID: PMC5159554 DOI: 10.1093/nar/gkw874] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 09/06/2016] [Accepted: 09/21/2016] [Indexed: 12/14/2022] Open
Abstract
Centromeres consist of DNA repeats in many eukaryotes. Non-allelic homologous recombination (HR) between them can result in gross chromosomal rearrangements (GCRs). In fission yeast, Rad51 suppresses isochromosome formation that occurs between inverted repeats in the centromere. However, how the HR enzyme prevents homology-mediated GCRs remains unclear. Here, we provide evidence that Rad51 with the aid of the Swi/Snf-type motor protein Rad54 promotes non-crossover recombination between centromere repeats to prevent isochromosome formation. Mutations in Rad51 and Rad54 epistatically increased the rates of isochromosome formation and chromosome loss. In sharp contrast, these mutations decreased gene conversion between inverted repeats in the centromere. Remarkably, analysis of recombinant DNAs revealed that rad51 and rad54 increase the proportion of crossovers. In the absence of Rad51, deletion of the structure-specific endonuclease Mus81 decreased both crossovers and isochromosomes, while the cdc27/pol32-D1 mutation, which impairs break-induced replication, did not. We propose that Rad51 and Rad54 promote non-crossover recombination between centromere repeats on the same chromatid, thereby suppressing crossover between non-allelic repeats on sister chromatids that leads to chromosomal rearrangements. Furthermore, we found that Rad51 and Rad54 are required for gene silencing in centromeres, suggesting that HR also plays a role in the structure and function of centromeres.
Collapse
Affiliation(s)
- Atsushi T Onaka
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Naoko Toyofuku
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Takahiro Inoue
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Akiko K Okita
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Minami Sagawa
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Jie Su
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Takeshi Shitanda
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Rei Matsuyama
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Faria Zafar
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Tatsuro S Takahashi
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Hisao Masukata
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Takuro Nakagawa
- Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| |
Collapse
|
26
|
Ishchuk OP, Vojvoda Zeljko T, Schifferdecker AJ, Mebrahtu Wisén S, Hagström ÅK, Rozpędowska E, Rørdam Andersen M, Hellborg L, Ling Z, Sibirny AA, Piškur J. Novel Centromeric Loci of the Wine and Beer Yeast Dekkera bruxellensis CEN1 and CEN2. PLoS One 2016; 11:e0161741. [PMID: 27560164 PMCID: PMC4999066 DOI: 10.1371/journal.pone.0161741] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/10/2016] [Indexed: 11/19/2022] Open
Abstract
The wine and beer yeast Dekkera bruxellensis thrives in environments that are harsh and limiting, especially in concentrations with low oxygen and high ethanol. Its different strains’ chromosomes greatly vary in number (karyotype). This study isolates two novel centromeric loci (CEN1 and CEN2), which support both the yeast’s autonomous replication and the stable maintenance of plasmids. In the sequenced genome of the D. bruxellensis strain CBS 2499, CEN1 and CEN2 are each present in one copy. They differ from the known “point” CEN elements, and their biological activity is retained within ~900–1300 bp DNA segments. CEN1 and CEN2 have features of both “point” and “regional” centromeres: They contain conserved DNA elements, ARSs, short repeats, one tRNA gene, and transposon-like elements within less than 1 kb. Our discovery of a miniature inverted-repeat transposable element (MITE) next to CEN2 is the first report of such transposons in yeast. The transformants carrying circular plasmids with cloned CEN1 and CEN2 undergo a phenotypic switch: They form fluffy colonies and produce three times more biofilm. The introduction of extra copies of CEN1 and CEN2 promotes both genome rearrangements and ploidy shifts, with these effects mediated by homologous recombination (between circular plasmid and genome centromere copy) or by chromosome breakage when integrated. Also, the proximity of the MITE-like transposon to CEN2 could translocate CEN2 within the genome or cause chromosomal breaks, so promoting genome dynamics. With extra copies of CEN1 and CEN2, the yeast’s enhanced capacities to rearrange its genome and to change its gene expression could increase its abilities for exploiting new and demanding niches.
Collapse
Affiliation(s)
- Olena P. Ishchuk
- Department of Biology, Lund University, Lund, Sweden
- Department of Molecular Genetics and Biotechnology, Institute of Cell Biology, NAS of Ukraine, Lviv, Ukraine
- * E-mail:
| | - Tanja Vojvoda Zeljko
- Department of Biology, Lund University, Lund, Sweden
- Division of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | | | | | | | | | | | | | - Zhihao Ling
- Department of Biology, Lund University, Lund, Sweden
| | - Andrei A. Sibirny
- Department of Molecular Genetics and Biotechnology, Institute of Cell Biology, NAS of Ukraine, Lviv, Ukraine
- Department of Biotechnology and Microbiology, University of Rzeszow, Rzeszow, Poland
| | - Jure Piškur
- Department of Biology, Lund University, Lund, Sweden
| |
Collapse
|
27
|
Scott KC, Bloom KS. Lessons learned from counting molecules: how to lure CENP-A into the kinetochore. Open Biol 2015; 4:rsob.140191. [PMID: 25500356 PMCID: PMC4281711 DOI: 10.1098/rsob.140191] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Affiliation(s)
- Kristin C Scott
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, USA
| | - Kerry S Bloom
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
28
|
Replication stress in Mammalian cells and its consequences for mitosis. Genes (Basel) 2015; 6:267-98. [PMID: 26010955 PMCID: PMC4488665 DOI: 10.3390/genes6020267] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 05/15/2015] [Accepted: 05/18/2015] [Indexed: 12/23/2022] Open
Abstract
The faithful transmission of genetic information to daughter cells is central to maintaining genomic stability and relies on the accurate and complete duplication of genetic material during each cell cycle. However, the genome is routinely exposed to endogenous and exogenous stresses that can impede the progression of replication. Such replication stress can be an early cause of cancer or initiate senescence. Replication stress, which primarily occurs during S phase, results in consequences during mitosis, jeopardizing chromosome segregation and, in turn, genomic stability. The traces of replication stress can be detected in the daughter cells during G1 phase. Alterations in mitosis occur in two types: 1) local alterations that correspond to breaks, rearrangements, intertwined DNA molecules or non-separated sister chromatids that are confined to the region of the replication dysfunction; 2) genome-wide chromosome segregation resulting from centrosome amplification (although centrosomes do not contain DNA), which amplifies the local replication stress to the entire genome. Here, we discuss the endogenous causes of replication perturbations, the mechanisms of replication fork restart and the consequences for mitosis, chromosome segregation and genomic stability.
Collapse
|
29
|
Abstract
Replication stress is a significant contributor to genome instability. Recent studies suggest that the centromere is particularly susceptible to replication stress and prone to rearrangements and genome damage, as well as chromosome loss. This effect is enhanced by loss of heterochromatin. The resulting changes in genetic organization, including chromosome loss, increased mutation and loss of heterozygosity, are important contributors to malignant growth.
Collapse
|
30
|
Emerging roles for centromere-associated proteins in DNA repair and genetic recombination. Biochem Soc Trans 2014; 41:1726-30. [PMID: 24256282 DOI: 10.1042/bst20130200] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Centromere proteins CENP-S and CENP-X are members of the constitutive centromere-associated network, which is a conserved group of proteins that are needed for the assembly and function of kinetochores at centromeres. Intriguingly CENP-S and CENP-X have alter egos going by the names of MHF1 (FANCM-associated histone-fold protein 1) and MHF2 respectively. In this guise they function with a DNA translocase called FANCM (Fanconi's anemia complementation group M) to promote DNA repair and homologous recombination. In the present review we discuss current knowledge of the biological roles of CENP-S and CENP-X and how their dual existence may be a common feature of CCAN (constitutive centromere-associated network) proteins.
Collapse
|
31
|
The origins and processing of ultra fine anaphase DNA bridges. Curr Opin Genet Dev 2014; 26:1-5. [PMID: 24795279 DOI: 10.1016/j.gde.2014.03.003] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/13/2014] [Accepted: 03/12/2014] [Indexed: 01/26/2023]
Abstract
Ultra-fine DNA bridges (UFBs) are a recently identified class of mitotic DNA structures that cannot be visualized using conventional DNA staining methods (e.g. using DAPI). Their existence can currently only be revealed by immuno-fluorescent staining for proteins that bind to them, including PICH and BLM. UFBs become visible in the anaphase of mitosis, and can persist into telophase in rare cases. There are at least three different types of UFBs that can be distinguished according to the chromosomal loci from which they originate. However, it remains largely unknown how these UFBs are generated or resolved in the cell. In this article, we will review our current understanding of different types of UFBs and the potential functional role of the proteins that have been shown to be associated with them.
Collapse
|
32
|
Centromeric barrier disruption leads to mitotic defects in Schizosaccharomyces pombe. G3-GENES GENOMES GENETICS 2014; 4:633-42. [PMID: 24531725 PMCID: PMC4059236 DOI: 10.1534/g3.114.010397] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Centromeres are cis-acting chromosomal domains that direct kinetochore formation, enabling faithful chromosome segregation and preserving genome stability. The centromeres of most eukaryotic organisms are structurally complex, composed of nonoverlapping, structurally and functionally distinct chromatin subdomains, including the specialized core chromatin that underlies the kinetochore and pericentromeric heterochromatin. The genomic and epigenetic features that specify and preserve the adjacent chromatin subdomains critical to centromere identity are currently unknown. Here we demonstrate that chromatin barriers regulate this process in Schizosaccharomyces pombe. Reduced fitness and mitotic chromosome segregation defects occur in strains that carry exogenous DNA inserted at centromere 1 chromatin barriers. Abnormal phenotypes are accompanied by changes in the structural integrity of both the centromeric core chromatin domain, containing the conserved CENP-ACnp1 protein, and the flanking pericentric heterochromatin domain. Barrier mutant cells can revert to wild-type growth and centromere structure at a high frequency after the spontaneous excision of integrated exogenous DNA. Our results reveal a previously undemonstrated role for chromatin barriers in chromosome segregation and in the prevention of genome instability.
Collapse
|
33
|
Mankouri HW, Huttner D, Hickson ID. How unfinished business from S-phase affects mitosis and beyond. EMBO J 2013; 32:2661-71. [PMID: 24065128 PMCID: PMC3801442 DOI: 10.1038/emboj.2013.211] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 09/05/2013] [Indexed: 12/17/2022] Open
Abstract
The eukaryotic cell cycle is conventionally viewed as comprising several discrete steps, each of which must be completed before the next one is initiated. However, emerging evidence suggests that incompletely replicated, or unresolved, chromosomes from S-phase can persist into mitosis, where they present a potential threat to the faithful segregation of sister chromatids. In this review, we provide an overview of the different classes of loci where this 'unfinished S-phase business' can lead to a variety of cytogenetically distinct DNA structures throughout the various steps of mitosis. Furthermore, we discuss the potential ways in which cells might not only tolerate this inevitable aspect of chromosome biology, but also exploit it to assist in the maintenance of genome stability.
Collapse
Affiliation(s)
- Hocine W Mankouri
- Department of Cellular and Molecular Medicine, Nordea Center for Healthy Aging, Copenhagen N, Denmark
| | - Diana Huttner
- Department of Cellular and Molecular Medicine, Nordea Center for Healthy Aging, Copenhagen N, Denmark
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen N, Denmark
| | - Ian D Hickson
- Department of Cellular and Molecular Medicine, Nordea Center for Healthy Aging, Copenhagen N, Denmark
| |
Collapse
|
34
|
Bhattacharjee S, Osman F, Feeney L, Lorenz A, Bryer C, Whitby MC. MHF1-2/CENP-S-X performs distinct roles in centromere metabolism and genetic recombination. Open Biol 2013; 3:130102. [PMID: 24026537 PMCID: PMC3787749 DOI: 10.1098/rsob.130102] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The histone-fold proteins Mhf1/CENP-S and Mhf2/CENP-X perform two important functions in vertebrate cells. First, they are components of the constitutive centromere-associated network, aiding kinetochore assembly and function. Second, they work with the FANCM DNA translocase to promote DNA repair. However, it has been unclear whether there is crosstalk between these roles. We show that Mhf1 and Mhf2 in fission yeast, as in vertebrates, serve a dual function, aiding DNA repair/recombination and localizing to centromeres to promote chromosome segregation. Importantly, these functions are distinct, with the former being dependent on their interaction with the FANCM orthologue Fml1 and the latter not. Together with Fml1, they play a second role in aiding chromosome segregation by processing sister chromatid junctions. However, a failure of this activity does not manifest dramatically increased levels of chromosome missegregation due to the Mus81–Eme1 endonuclease, which acts as a failsafe to resolve DNA junctions before the end of mitosis.
Collapse
Affiliation(s)
- Sonali Bhattacharjee
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | | | | | | | | | | |
Collapse
|
35
|
Norman-Axelsson U, Durand-Dubief M, Prasad P, Ekwall K. DNA topoisomerase III localizes to centromeres and affects centromeric CENP-A levels in fission yeast. PLoS Genet 2013; 9:e1003371. [PMID: 23516381 PMCID: PMC3597498 DOI: 10.1371/journal.pgen.1003371] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 01/25/2013] [Indexed: 11/21/2022] Open
Abstract
Centromeres are specialized chromatin regions marked by the presence of nucleosomes containing the centromere-specific histone H3 variant CENP-A, which is essential for chromosome segregation. Assembly and disassembly of nucleosomes is intimately linked to DNA topology, and DNA topoisomerases have previously been implicated in the dynamics of canonical H3 nucleosomes. Here we show that Schizosaccharomyces pombe Top3 and its partner Rqh1 are involved in controlling the levels of CENP-ACnp1 at centromeres. Both top3 and rqh1 mutants display defects in chromosome segregation. Using chromatin immunoprecipitation and tiling microarrays, we show that Top3, unlike Top1 and Top2, is highly enriched at centromeric central domains, demonstrating that Top3 is the major topoisomerase in this region. Moreover, centromeric Top3 occupancy positively correlates with CENP-ACnp1 occupancy. Intriguingly, both top3 and rqh1 mutants display increased relative enrichment of CENP-ACnp1 at centromeric central domains. Thus, Top3 and Rqh1 normally limit the levels of CENP-ACnp1 in this region. This new role is independent of the established function of Top3 and Rqh1 in homologous recombination downstream of Rad51. Therefore, we hypothesize that the Top3-Rqh1 complex has an important role in controlling centromere DNA topology, which in turn affects the dynamics of CENP-ACnp1 nucleosomes. Centromeres are unique regions on eukaryotic chromosomes that are essential for chromosome segregation at mitosis and meiosis. Centromere identity and function depends on the presence of specialized chromatin with nucleosomes containing the centromere-specific histone H3 variant CENP-A. Assembly and disassembly of nucleosomes have previously been shown to involve a family of enzymes known as DNA topoisomerases. We show that centromeres are unique in that they are associated with high levels of Top3, but low levels of Top1 and Top2, suggesting that Top3 is particularly important for centromeric DNA topology. Impaired function of Top3 or its partner Rqh1 results in chromosome segregation defects and increased levels of CENP-ACnp1 at centromeres. This role in limiting the levels of CENP-ACnp1 at centromeres is independent of the established role for the Top3-Rqh1 complex in homologous recombination. Therefore, we hypothesize that the Top3-Rqh1 complex exerts this effect by regulating centromere DNA topology, which in turn affects CENP-ACnp1 nucleosome dynamics. Specific removal of negative supercoiling by Top3 could directly have a negative effect on assembly of CENP-ACnp1 nucleosomes with left-handed negative wrapping of DNA and/or act indirectly by inhibiting transcription-coupled CENP-ACnp1 assembly. Alternatively, Top3 may be a factor that promotes formation of CENP-ACnp1 hemisomes with right-handed wrapping of DNA over conventional octamers. This suggests a new role for the Top3-Rqh1 complex at centromeres and may contribute to the understanding of the structural and functional specification of centromeres.
Collapse
Affiliation(s)
- Ulrika Norman-Axelsson
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Mickaël Durand-Dubief
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Punit Prasad
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Karl Ekwall
- Center for Biosciences, Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
- * E-mail:
| |
Collapse
|
36
|
Li PC, Petreaca RC, Jensen A, Yuan JP, Green MD, Forsburg SL. Replication fork stability is essential for the maintenance of centromere integrity in the absence of heterochromatin. Cell Rep 2013; 3:638-45. [PMID: 23478021 DOI: 10.1016/j.celrep.2013.02.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 01/06/2013] [Accepted: 02/05/2013] [Indexed: 12/18/2022] Open
Abstract
The centromere of many eukaryotes contains highly repetitive sequences marked by methylation of histone H3K9 by Clr4(KMT1). This recruits multiple heterochromatin proteins, including Swi6 and Chp1, to form a rigid centromere and ensure accurate chromosome segregation. In the absence of heterochromatin, cells show an increased rate of recombination in the centromere, as well as chromosome loss. These defects are severely aggravated by loss of replication fork stability. Thus, heterochromatin proteins and replication fork protection mechanisms work in concert to prevent abnormal recombination, preserve centromere integrity, and ensure faithful chromosome segregation.
Collapse
Affiliation(s)
- Pao-Chen Li
- Molecular & Computational Biology Program, University of Southern California, Los Angeles, CA 90089-2910, USA
| | | | | | | | | | | |
Collapse
|
37
|
Neumann P, Navrátilová A, Schroeder-Reiter E, Koblížková A, Steinbauerová V, Chocholová E, Novák P, Wanner G, Macas J. Stretching the rules: monocentric chromosomes with multiple centromere domains. PLoS Genet 2012; 8:e1002777. [PMID: 22737088 PMCID: PMC3380829 DOI: 10.1371/journal.pgen.1002777] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 05/05/2012] [Indexed: 11/29/2022] Open
Abstract
The centromere is a functional chromosome domain that is essential for faithful chromosome segregation during cell division and that can be reliably identified by the presence of the centromere-specific histone H3 variant CenH3. In monocentric chromosomes, the centromere is characterized by a single CenH3-containing region within a morphologically distinct primary constriction. This region usually spans up to a few Mbp composed mainly of centromere-specific satellite DNA common to all chromosomes of a given species. In holocentric chromosomes, there is no primary constriction; the centromere is composed of many CenH3 loci distributed along the entire length of a chromosome. Using correlative fluorescence light microscopy and high-resolution electron microscopy, we show that pea (Pisum sativum) chromosomes exhibit remarkably long primary constrictions that contain 3-5 explicit CenH3-containing regions, a novelty in centromere organization. In addition, we estimate that the size of the chromosome segment delimited by two outermost domains varies between 69 Mbp and 107 Mbp, several factors larger than any known centromere length. These domains are almost entirely composed of repetitive DNA sequences belonging to 13 distinct families of satellite DNA and one family of centromeric retrotransposons, all of which are unevenly distributed among pea chromosomes. We present the centromeres of Pisum as novel "meta-polycentric" functional domains. Our results demonstrate that the organization and DNA composition of functional centromere domains can be far more complex than previously thought, do not require single repetitive elements, and do not require single centromere domains in order to segregate properly. Based on these findings, we propose Pisum as a useful model for investigation of centromere architecture and the still poorly understood role of repetitive DNA in centromere evolution, determination, and function.
Collapse
Affiliation(s)
- Pavel Neumann
- Biology Centre of the Academy of Sciences of the Czech Republic, Institute of Plant Molecular Biology, České Budějovice, Czech Republic.
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Ruiz-Herrera A, Smirnova A, Khoriauli L, Nergadze SG, Mondello C, Giulotto E. Gene amplification in human cells knocked down for RAD54. Genome Integr 2011; 2:5. [PMID: 21418575 PMCID: PMC3074559 DOI: 10.1186/2041-9414-2-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Accepted: 03/18/2011] [Indexed: 12/18/2022] Open
Abstract
Background In mammalian cells gene amplification is a common manifestation of genome instability promoted by DNA double-strand breaks (DSBs). The repair of DSBs mainly occurs through two mechanisms: non-homologous end-joining (NHEJ) and homologous recombination (HR). We previously showed that defects in the repair of DSBs via NHEJ could increase the frequency of gene amplification. In this paper we explored whether a single or a combined defect in DSBs repair pathways can affect gene amplification. Results We constructed human cell lines in which the expression of RAD54 and/or DNA-PKcs was constitutively knocked-down by RNA interference. We analyzed their radiosensitivity and their capacity to generate amplified DNA. Our results showed that both RAD54 and DNA-PKcs deficient cells are hypersensitive to γ-irradiation and generate methotrexate resistant colonies at a higher frequency compared to the proficient cell lines. In addition, the analysis of the cytogenetic organization of the amplicons revealed that isochromosome formation is a prevalent mechanism responsible for copy number increase in RAD54 defective cells. Conclusions Defects in the DSBs repair mechanisms can influence the organization of amplified DNA. The high frequency of isochromosome formation in cells deficient for RAD54 suggests that homologous recombination proteins might play a role in preventing rearrangements at the centromeres.
Collapse
Affiliation(s)
- Aurora Ruiz-Herrera
- Dipartimento di Genetica e Microbiologia "Adriano Buzzati-Traverso", Università di Pavia, Via Ferrata 1, 27100 Pavia, Italy.
| | | | | | | | | | | |
Collapse
|