1
|
Lim KK, Lam UTF, Li Y, Zeng YB, Yang H, Chen ES. Set2 regulates Ccp1 and Swc2 to ensure centromeric stability by retargeting CENP-A. Nucleic Acids Res 2024; 52:4198-4214. [PMID: 38442274 PMCID: PMC11077061 DOI: 10.1093/nar/gkae084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 01/24/2024] [Accepted: 01/29/2024] [Indexed: 03/07/2024] Open
Abstract
Precise positioning of the histone-H3 variant, CENP-A, ensures centromere stability and faithful chromosomal segregation. Mislocalization of CENP-A to extra-centromeric loci results in aneuploidy and compromised cell viability associated with formation of ectopic kinetochores. The mechanism that retargets mislocalized CENP-A back to the centromere is unclarified. We show here that the downregulation of the histone H3 lysine 36 (H3K36) methyltransferase Set2 can preserve centromere localization of a temperature-sensitive mutant cnp1-1 Schizosaccharomyces pombe CENP-A (SpCENP-A) protein and reverse aneuploidy by redirecting mislocalized SpCENP-A back to centromere from ribosomal DNA (rDNA) loci, which serves as a sink for the delocalized SpCENP-A. Downregulation of set2 augments Swc2 (SWR1 complex DNA-binding module) expression and releases histone chaperone Ccp1 from the centromeric reservoir. Swc2 and Ccp1 are directed to the rDNA locus to excavate the SpCENP-Acnp1-1, which is relocalized to the centromere in a manner dependent on canonical SpCENP-A loaders, including Mis16, Mis17 and Mis18, thereby conferring cell survival and safeguarding chromosome segregation fidelity. Chromosome missegregation is a severe genetic instability event that compromises cell viability. This mechanism thus promotes CENP-A presence at the centromere to maintain genomic stability.
Collapse
Affiliation(s)
- Kim Kiat Lim
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ulysses Tsz Fung Lam
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ying Li
- NUS Center for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Cancer Science Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Yi Bing Zeng
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Henry Yang
- NUS Center for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Cancer Science Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- National University Health System, Singapore
| | - Ee Sin Chen
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- NUS Center for Cancer Research, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- National University Health System, Singapore
- Integrative Sciences & Engineering Programme, National University of Singapore, Singapore
| |
Collapse
|
2
|
Caro L, Raman P, Steiner FA, Ailion M, Malik HS. Recurrent but Short-Lived Duplications of Centromeric Proteins in Holocentric Caenorhabditis Species. Mol Biol Evol 2022; 39:6731087. [PMID: 36173809 PMCID: PMC9577544 DOI: 10.1093/molbev/msac206] [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: 12/15/2022] Open
Abstract
Centromeric histones (CenH3s) are essential for chromosome inheritance during cell division in most eukaryotes. CenH3 genes have rapidly evolved and undergone repeated gene duplications and diversification in many plant and animal species. In Caenorhabditis species, two independent duplications of CenH3 (named hcp-3 for HoloCentric chromosome-binding Protein 3) were previously identified in C. elegans and C. remanei. Using phylogenomic analyses in 32 Caenorhabditis species, we find strict retention of the ancestral hcp-3 gene and 10 independent duplications. Most hcp-3L (hcp-3-like) paralogs are only found in 1-2 species, are expressed in both males and females/hermaphrodites, and encode histone fold domains with 69-100% identity to ancestral hcp-3. We identified novel N-terminal protein motifs, including putative kinetochore protein-interacting motifs and a potential separase cleavage site, which are well conserved across Caenorhabditis HCP-3 proteins. Other N-terminal motifs vary in their retention across paralogs or species, revealing potential subfunctionalization or functional loss following duplication. An N-terminal extension in the hcp-3L gene of C. afra revealed an unprecedented protein fusion, where hcp-3L fused to duplicated segments from hcp-4 (nematode CENP-C). By extending our analyses beyond CenH3, we found gene duplications of six inner and outer kinetochore genes in Caenorhabditis, which appear to have been retained independent of hcp-3 duplications. Our findings suggest that centromeric protein duplications occur frequently in Caenorhabditis nematodes, are selectively retained for short evolutionary periods, then degenerate or are lost entirely. We hypothesize that unique challenges associated with holocentricity in Caenorhabditis may lead to this rapid "revolving door" of kinetochore protein paralogs.
Collapse
Affiliation(s)
- Lews Caro
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA.,Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Pravrutha Raman
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Florian A Steiner
- Department of Molecular Biology and Cellular Biology, Section of Biology, Faculty of Sciences, University of Geneva, Geneva, Switzerland
| | - Michael Ailion
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA.,Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Harmit S Malik
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA.,Howard Hughes Medical Institute, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| |
Collapse
|
3
|
Wang Y, Wu L, Yuen KWY. The roles of transcription, chromatin organisation and chromosomal processes in holocentromere establishment and maintenance. Semin Cell Dev Biol 2022; 127:79-89. [PMID: 35042676 DOI: 10.1016/j.semcdb.2022.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 01/09/2022] [Accepted: 01/09/2022] [Indexed: 12/15/2022]
Abstract
The centromere is a unique functional region on each eukaryotic chromosome where the kinetochore assembles and orchestrates microtubule attachment and chromosome segregation. Unlike monocentromeres that occupy a specific region on the chromosome, holocentromeres are diffused along the length of the chromosome. Despite being less common, holocentromeres have been verified in almost 800 nematode, insect, and plant species. Understanding of the molecular and epigenetic regulation of holocentromeres is lagging that of monocentromeres. Here we review how permissive locations for holocentromeres are determined across the genome, potentially by chromatin organisation, transcription, and non-coding RNAs, specifically in the nematode C. elegans. In addition, we discuss how holocentric CENP-A or CENP-T-containing nucleosomes are recruited and deposited, through the help of histone chaperones, licensing factors, and condensin complexes, both during de novo holocentromere establishment, and in each mitotic cell cycle. The process of resolving sister centromeres after DNA replication in holocentric organisms is also mentioned. Conservation and diversity between holocentric and monocentric organisms are highlighted, and outstanding questions are proposed.
Collapse
Affiliation(s)
- Yue Wang
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Lillian Wu
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong; Epigenetics and Genome Stability Team, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, United Kingdom
| | - Karen Wing Yee Yuen
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong.
| |
Collapse
|
4
|
Sundararajan K, Straight AF. Centromere Identity and the Regulation of Chromosome Segregation. Front Cell Dev Biol 2022; 10:914249. [PMID: 35721504 PMCID: PMC9203049 DOI: 10.3389/fcell.2022.914249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/13/2022] [Indexed: 11/13/2022] Open
Abstract
Eukaryotes segregate their chromosomes during mitosis and meiosis by attaching chromosomes to the microtubules of the spindle so that they can be distributed into daughter cells. The complexity of centromeres ranges from the point centromeres of yeast that attach to a single microtubule to the more complex regional centromeres found in many metazoans or holocentric centromeres of some nematodes, arthropods and plants, that bind to dozens of microtubules per kinetochore. In vertebrates, the centromere is defined by a centromere specific histone variant termed Centromere Protein A (CENP-A) that replaces histone H3 in a subset of centromeric nucleosomes. These CENP-A nucleosomes are distributed on long stretches of highly repetitive DNA and interspersed with histone H3 containing nucleosomes. The mechanisms by which cells control the number and position of CENP-A nucleosomes is unknown but likely important for the organization of centromeric chromatin in mitosis so that the kinetochore is properly oriented for microtubule capture. CENP-A chromatin is epigenetically determined thus cells must correct errors in CENP-A organization to prevent centromere dysfunction and chromosome loss. Recent improvements in sequencing complex centromeres have paved the way for defining the organization of CENP-A nucleosomes in centromeres. Here we discuss the importance and challenges in understanding CENP-A organization and highlight new discoveries and advances enabled by recent improvements in the human genome assembly.
Collapse
|
5
|
The ins and outs of CENP-A: Chromatin dynamics of the centromere-specific histone. Semin Cell Dev Biol 2022; 135:24-34. [PMID: 35422390 DOI: 10.1016/j.semcdb.2022.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/05/2022] [Accepted: 04/05/2022] [Indexed: 01/08/2023]
Abstract
Centromeres are highly specialised chromosome domains defined by the presence of an epigenetic mark, the specific histone H3 variant called CENP-A (centromere protein A). They constitute the genomic regions on which kinetochores form and when defective cause segregation defects that can lead to aneuploidy and cancer. Here, we discuss how CENP-A is established and maintained to propagate centromere identity while subjected to dynamic chromatin remodelling during essential cellular processes like DNA repair, replication, and transcription. We highlight parallels and identify conserved mechanisms between different model organism with a particular focus on 1) the establishment of CENP-A at centromeres, 2) CENP-A maintenance during transcription and replication, and 3) the mechanisms that help preventing CENP-A localization at non-centromeric sites. We then give examples of how timely loading of new CENP-A to the centromere, maintenance of old CENP-A during S-phase and transcription, and removal of CENP-A at non-centromeric sites are coordinated and controlled by an intricate network of factors whose identity is slowly being unravelled.
Collapse
|
6
|
Özdemir I, Steiner FA. Transmission of chromatin states across generations in C. elegans. Semin Cell Dev Biol 2021; 127:133-141. [PMID: 34823984 DOI: 10.1016/j.semcdb.2021.11.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 11/08/2021] [Accepted: 11/10/2021] [Indexed: 11/18/2022]
Abstract
Epigenetic inheritance refers to the transmission of phenotypes across generations without affecting the genomic DNA sequence. Even though it has been documented in many species in fungi, animals and plants, the mechanisms underlying epigenetic inheritance are not fully uncovered. Epialleles, the heritable units of epigenetic information, can take the form of several biomolecules, including histones and their post-translational modifications (PTMs). Here, we review the recent advances in the understanding of the transmission of histone variants and histone PTM patterns across generations in C. elegans. We provide a general overview of the intergenerational and transgenerational inheritance of histone PTMs and their modifiers and discuss the interplay among different histone PTMs. We also evaluate soma-germ line communication and its impact on the inheritance of epigenetic traits.
Collapse
Affiliation(s)
- Isa Özdemir
- Department of Molecular Biology and Institute of Genetics and Genomics in Geneva, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland
| | - Florian A Steiner
- Department of Molecular Biology and Institute of Genetics and Genomics in Geneva, Section of Biology, Faculty of Sciences, University of Geneva, 1211 Geneva, Switzerland.
| |
Collapse
|
7
|
Lin Z, Xie Y, Nong W, Ren X, Li R, Zhao Z, Hui JHL, Yuen KWY. Formation of artificial chromosomes in Caenorhabditis elegans and analyses of their segregation in mitosis, DNA sequence composition and holocentromere organization. Nucleic Acids Res 2021; 49:9174-9193. [PMID: 34417622 PMCID: PMC8450109 DOI: 10.1093/nar/gkab690] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 07/23/2021] [Accepted: 07/30/2021] [Indexed: 11/14/2022] Open
Abstract
To investigate how exogenous DNA concatemerizes to form episomal artificial chromosomes (ACs), acquire equal segregation ability and maintain stable holocentromeres, we injected DNA sequences with different features, including sequences that are repetitive or complex, and sequences with different AT-contents, into the gonad of Caenorhabditis elegans to form ACs in embryos, and monitored AC mitotic segregation. We demonstrated that AT-poor sequences (26% AT-content) delayed the acquisition of segregation competency of newly formed ACs. We also co-injected fragmented Saccharomyces cerevisiae genomic DNA, differentially expressed fluorescent markers and ubiquitously expressed selectable marker to construct a less repetitive, more complex AC. We sequenced the whole genome of a strain which propagates this AC through multiple generations, and de novo assembled the AC sequences. We discovered CENP-AHCP-3 domains/peaks are distributed along the AC, as in endogenous chromosomes, suggesting a holocentric architecture. We found that CENP-AHCP-3 binds to the unexpressed marker genes and many fragmented yeast sequences, but is excluded in the yeast extremely high-AT-content centromeric and mitochondrial DNA (> 83% AT-content) on the AC. We identified A-rich motifs in CENP-AHCP-3 domains/peaks on the AC and on endogenous chromosomes, which have some similarity with each other and similarity to some non-germline transcription factor binding sites.
Collapse
Affiliation(s)
- Zhongyang Lin
- School of Biological Sciences, the University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Yichun Xie
- School of Life Sciences, Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Wenyan Nong
- School of Life Sciences, Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Xiaoliang Ren
- Department of Biology, Baptist University of Hong Kong, Sir Run Run Shaw Building, Ho Sin Hang Campus, Kowloon Tong, Hong Kong
| | - Runsheng Li
- Department of Biology, Baptist University of Hong Kong, Sir Run Run Shaw Building, Ho Sin Hang Campus, Kowloon Tong, Hong Kong
| | - Zhongying Zhao
- Department of Biology, Baptist University of Hong Kong, Sir Run Run Shaw Building, Ho Sin Hang Campus, Kowloon Tong, Hong Kong
| | - Jerome Ho Lam Hui
- School of Life Sciences, Simon F.S. Li Marine Science Laboratory, State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong
| | - Karen Wing Yee Yuen
- School of Biological Sciences, the University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| |
Collapse
|
8
|
Lin Z, Yuen KWY. RbAp46/48LIN-53 and HAT-1 are required for initial CENP-AHCP-3 deposition and de novo holocentromere formation on artificial chromosomes in Caenorhabditis elegans embryos. Nucleic Acids Res 2021; 49:9154-9173. [PMID: 33872374 PMCID: PMC8450102 DOI: 10.1093/nar/gkab217] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/10/2021] [Accepted: 03/23/2021] [Indexed: 12/17/2022] Open
Abstract
Foreign DNA microinjected into the Caenorhabditis elegans syncytial gonad forms episomal extra-chromosomal arrays, or artificial chromosomes (ACs), in embryos. Short, linear DNA fragments injected concatemerize into high molecular weight (HMW) DNA arrays that are visible as punctate DAPI-stained foci in oocytes, and they undergo chromatinization and centromerization in embryos. The inner centromere, inner kinetochore and spindle checkpoint components, including AIR-2, CENP-AHCP-3, Mis18BP1KNL-2 and BUB-1, respectively, assemble onto the nascent ACs during the first mitosis. The DNA replication efficiency of ACs improves over several cell cycles, which correlates with the improvement of kinetochore bi-orientation and proper segregation of ACs. Depletion of condensin II subunits, like CAPG-2 and SMC-4, but not the replicative helicase component, MCM-2, reduces de novo CENP-AHCP-3 level on nascent ACs. Furthermore, H3K9ac, H4K5ac and H4K12ac are highly enriched on newly chromatinized ACs. RbAp46/48LIN-53 and HAT-1, which affect the acetylation of histone H3 and H4, are essential for chromatinization, de novo centromere formation and segregation competency of nascent ACs. RbAp46/48LIN-53 or HAT-1 depletion causes the loss of both CENP-AHCP-3 and Mis18BP1KNL-2 initial deposition at de novo centromeres on ACs. This phenomenon is different from centromere maintenance on endogenous chromosomes, where Mis18BP1KNL-2 functions upstream of RbAp46/48LIN-53.
Collapse
Affiliation(s)
- Zhongyang Lin
- School of Biological Sciences, The University of Hong Kong. Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Karen Wing Yee Yuen
- School of Biological Sciences, The University of Hong Kong. Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| |
Collapse
|
9
|
Ishikura S, Nakabayashi K, Nagai M, Tsunoda T, Shirasawa S. ZFAT binds to centromeres to control noncoding RNA transcription through the KAT2B-H4K8ac-BRD4 axis. Nucleic Acids Res 2020; 48:10848-10866. [PMID: 32997115 PMCID: PMC7641738 DOI: 10.1093/nar/gkaa815] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/09/2020] [Accepted: 09/17/2020] [Indexed: 02/07/2023] Open
Abstract
Centromeres are genomic regions essential for faithful chromosome segregation. Transcription of noncoding RNA (ncRNA) at centromeres is important for their formation and functions. Here, we report the molecular mechanism by which the transcriptional regulator ZFAT controls the centromeric ncRNA transcription in human and mouse cells. Chromatin immunoprecipitation with high-throughput sequencing analysis shows that ZFAT binds to centromere regions at every chromosome. We find a specific 8-bp DNA sequence for the ZFAT-binding motif that is highly conserved and widely distributed at whole centromere regions of every chromosome. Overexpression of ZFAT increases the centromeric ncRNA levels at specific chromosomes, whereas its silencing reduces them, indicating crucial roles of ZFAT in centromeric transcription. Overexpression of ZFAT increases the centromeric levels of both the histone acetyltransferase KAT2B and the acetylation at the lysine 8 in histone H4 (H4K8ac). siRNA-mediated knockdown of KAT2B inhibits the overexpressed ZFAT-induced increase in centromeric H4K8ac levels, suggesting that ZFAT recruits KAT2B to centromeres to induce H4K8ac. Furthermore, overexpressed ZFAT recruits the bromodomain-containing protein BRD4 to centromeres through KAT2B-mediated H4K8ac, leading to RNA polymerase II-dependent ncRNA transcription. Thus, ZFAT binds to centromeres to control ncRNA transcription through the KAT2B-H4K8ac-BRD4 axis.
Collapse
Affiliation(s)
- Shuhei Ishikura
- Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.,Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Kazuhiko Nakabayashi
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan
| | - Masayoshi Nagai
- Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Toshiyuki Tsunoda
- Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.,Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | - Senji Shirasawa
- Department of Cell Biology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.,Central Research Institute for Advanced Molecular Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| |
Collapse
|
10
|
Construction and analysis of artificial chromosomes with de novo holocentromeres in Caenorhabditis elegans. Essays Biochem 2020; 64:233-249. [PMID: 32756873 DOI: 10.1042/ebc20190067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/16/2020] [Accepted: 07/20/2020] [Indexed: 02/07/2023]
Abstract
Artificial chromosomes (ACs), generated in yeast (YACs) and human cells (HACs), have facilitated our understanding of the trans-acting proteins, cis-acting elements, such as the centromere, and epigenetic environments that are necessary to maintain chromosome stability. The centromere is the unique chromosomal region that assembles the kinetochore and connects to microtubules to orchestrate chromosome movement during cell division. While monocentromeres are the most commonly characterized centromere organization found in studied organisms, diffused holocentromeres along the chromosome length are observed in some plants, insects and nematodes. Based on the well-established DNA microinjection method in holocentric Caenorhabditis elegans, concatemerization of foreign DNA can efficiently generate megabase-sized extrachromosomal arrays (Exs), or worm ACs (WACs), for analyzing the mechanisms of WAC formation, de novo centromere formation, and segregation through mitosis and meiosis. This review summarizes the structural, size and stability characteristics of WACs. Incorporating LacO repeats in WACs and expressing LacI::GFP allows real-time tracking of newly formed WACs in vivo, whereas expressing LacI::GFP-chromatin modifier fusions can specifically adjust the chromatin environment of WACs. The WACs mature from passive transmission to autonomous segregation by establishing a holocentromere efficiently in a few cell cycles. Importantly, WAC formation does not require any C. elegans genomic DNA sequence. Thus, DNA substrates injected can be changed to evaluate the effects of DNA sequence and structure in WAC segregation. By injecting a complex mixture of DNA, a less repetitive WAC can be generated and propagated in successive generations for DNA sequencing and analysis of the established holocentromere on the WAC.
Collapse
|
11
|
Ólafsson G, Thorpe PH. Polo kinase recruitment via the constitutive centromere-associated network at the kinetochore elevates centromeric RNA. PLoS Genet 2020; 16:e1008990. [PMID: 32810142 PMCID: PMC7455000 DOI: 10.1371/journal.pgen.1008990] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/28/2020] [Accepted: 07/13/2020] [Indexed: 12/23/2022] Open
Abstract
The kinetochore, a multi-protein complex assembled on centromeres, is essential to segregate chromosomes during cell division. Deficiencies in kinetochore function can lead to chromosomal instability and aneuploidy-a hallmark of cancer cells. Kinetochore function is controlled by recruitment of regulatory proteins, many of which have been documented, however their function often remains uncharacterized and many are yet to be identified. To identify candidates of kinetochore regulation we used a proteome-wide protein association strategy in budding yeast and detected many proteins that are involved in post-translational modifications such as kinases, phosphatases and histone modifiers. We focused on the Polo-like kinase, Cdc5, and interrogated which cellular components were sensitive to constitutive Cdc5 localization. The kinetochore is particularly sensitive to constitutive Cdc5 kinase activity. Targeting Cdc5 to different kinetochore subcomplexes produced diverse phenotypes, consistent with multiple distinct functions at the kinetochore. We show that targeting Cdc5 to the inner kinetochore, the constitutive centromere-associated network (CCAN), increases the levels of centromeric RNA via an SPT4 dependent mechanism.
Collapse
Affiliation(s)
- Guðjón Ólafsson
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
| | - Peter H. Thorpe
- School of Biological and Chemical Sciences, Queen Mary, University of London, London, United Kingdom
| |
Collapse
|
12
|
Wong CYY, Ling YH, Mak JKH, Zhu J, Yuen KWY. "Lessons from the extremes: Epigenetic and genetic regulation in point monocentromere and holocentromere establishment on artificial chromosomes". Exp Cell Res 2020; 390:111974. [PMID: 32222413 DOI: 10.1016/j.yexcr.2020.111974] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 03/16/2020] [Accepted: 03/18/2020] [Indexed: 02/08/2023]
Abstract
The formation of de novo centromeres on artificial chromosomes in humans (HACs) and fission yeast (SpYACs) has provided much insights to the epigenetic and genetic control on regional centromere establishment and maintenance. Similarly, the use of artificial chromosomes in point centromeric budding yeast Saccharomyces cerevisiae (ScYACs) and holocentric Caenorhabditis elegans (WACs) has revealed epigenetic regulation in the originally thought purely genetically-determined point centromeres and some centromeric DNA sequence features in holocentromeres, respectively. These relatively extreme and less characterized centromere organizations, on the endogenous chromosomes and artificial chromosomes, will be discussed and compared to the more well-studied regional centromere systems. This review will highlight some of the common epigenetic and genetic features in different centromere architectures, including the presence of the centromeric histone H3 variant, CENP-A or CenH3, centromeric and pericentric transcription, AT-richness and repetitiveness of centromeric DNA sequences.
Collapse
Affiliation(s)
- Charmaine Yan Yu Wong
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Yick Hin Ling
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Jason Ka Ho Mak
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Jing Zhu
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong
| | - Karen Wing Yee Yuen
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong.
| |
Collapse
|
13
|
Ohzeki JI, Otake K, Masumoto H. Human artificial chromosome: Chromatin assembly mechanisms and CENP-B. Exp Cell Res 2020; 389:111900. [PMID: 32044309 DOI: 10.1016/j.yexcr.2020.111900] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 02/04/2020] [Accepted: 02/07/2020] [Indexed: 12/12/2022]
Abstract
The centromere is a specialized chromosomal locus required for accurate chromosome segregation. Heterochromatin also assembles around centromere chromatin and forms a base that supports sister chromatid cohesion until anaphase begins. Both centromere chromatin and heterochromatin assemble on a centromeric DNA sequence, a highly repetitive sequence called alphoid DNA (α-satellite DNA) in humans. Alphoid DNA can form a de novo centromere and subsequent human artificial chromosome (HAC) when introduced into the human culture cells HT1080. HAC is maintained stably as a single chromosome independent of other human chromosomes. For de novo centromere assembly and HAC formation, the centromere protein CENP-B and its binding sites, CENP-B boxes, are required in the repeating units of alphoid DNA. CENP-B has multiple roles in de novo centromere chromatin assembly and stabilization and in heterochromatin formation upon alphoid DNA introduction into the cells. Here we review recent progress in human artificial chromosome construction and centromere/heterochromatin assembly and maintenance, focusing on the involvement of human centromere DNA and CENP-B protein.
Collapse
Affiliation(s)
- Jun-Ichirou Ohzeki
- Laboratory of Chromosome Engineering, Department of Frontier Research and Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, 292-0818, Japan
| | - Koichiro Otake
- Laboratory of Chromosome Engineering, Department of Frontier Research and Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, 292-0818, Japan
| | - Hiroshi Masumoto
- Laboratory of Chromosome Engineering, Department of Frontier Research and Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, 292-0818, Japan.
| |
Collapse
|
14
|
Ling YH, Lin Z, Yuen KWY. Genetic and epigenetic effects on centromere establishment. Chromosoma 2019; 129:1-24. [PMID: 31781852 DOI: 10.1007/s00412-019-00727-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/24/2019] [Accepted: 10/10/2019] [Indexed: 01/19/2023]
Abstract
Endogenous chromosomes contain centromeres to direct equal chromosomal segregation in mitosis and meiosis. The location and function of existing centromeres is usually maintained through cell cycles and generations. Recent studies have investigated how the centromere-specific histone H3 variant CENP-A is assembled and replenished after DNA replication to epigenetically propagate the centromere identity. However, existing centromeres occasionally become inactivated, with or without change in underlying DNA sequences, or lost after chromosomal rearrangements, resulting in acentric chromosomes. New centromeres, known as neocentromeres, may form on ectopic, non-centromeric chromosomal regions to rescue acentric chromosomes from being lost, or form dicentric chromosomes if the original centromere is still active. In addition, de novo centromeres can form after chromatinization of purified DNA that is exogenously introduced into cells. Here, we review the phenomena of naturally occurring and experimentally induced new centromeres and summarize the genetic (DNA sequence) and epigenetic features of these new centromeres. We compare the characteristics of new and native centromeres to understand whether there are different requirements for centromere establishment and propagation. Based on our understanding of the mechanisms of new centromere formation, we discuss the perspectives of developing more stably segregating human artificial chromosomes to facilitate gene delivery in therapeutics and research.
Collapse
Affiliation(s)
- Yick Hin Ling
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Zhongyang Lin
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Karen Wing Yee Yuen
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong.
| |
Collapse
|
15
|
Nance J, Frøkjær-Jensen C. The Caenorhabditis elegans Transgenic Toolbox. Genetics 2019; 212:959-990. [PMID: 31405997 PMCID: PMC6707460 DOI: 10.1534/genetics.119.301506] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/01/2019] [Indexed: 12/30/2022] Open
Abstract
The power of any genetic model organism is derived, in part, from the ease with which gene expression can be manipulated. The short generation time and invariant developmental lineage have made Caenorhabditis elegans very useful for understanding, e.g., developmental programs, basic cell biology, neurobiology, and aging. Over the last decade, the C. elegans transgenic toolbox has expanded considerably, with the addition of a variety of methods to control expression and modify genes with unprecedented resolution. Here, we provide a comprehensive overview of transgenic methods in C. elegans, with an emphasis on recent advances in transposon-mediated transgenesis, CRISPR/Cas9 gene editing, conditional gene and protein inactivation, and bipartite systems for temporal and spatial control of expression.
Collapse
Affiliation(s)
- Jeremy Nance
- Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, Department of Cell Biology, New York University School of Medicine, New York 10016
| | - Christian Frøkjær-Jensen
- King Abdullah University of Science and Technology (KAUST), Biological and Environmental Science and Engineering Division (BESE), KAUST Environmental Epigenetics Program (KEEP), Thuwal 23955-6900, Saudi Arabia
| |
Collapse
|
16
|
Ohzeki J, Larionov V, Earnshaw WC, Masumoto H. De novo formation and epigenetic maintenance of centromere chromatin. Curr Opin Cell Biol 2019; 58:15-25. [PMID: 30654232 DOI: 10.1016/j.ceb.2018.12.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/30/2018] [Accepted: 12/07/2018] [Indexed: 12/12/2022]
Abstract
Accurate chromosome segregation is essential for cell proliferation. The centromere is a specialized chromosomal locus, on which the kinetochore structure is formed. The centromere/kinetochore is required for the equal separation of sister chromatids to daughter cells. Here, we review recent findings on centromere-specific chromatin, including its constitutive protein components, its de novo formation and maintenance mechanisms, and our progress in analyses with synthetic human artificial chromosomes (HACs).
Collapse
Affiliation(s)
- Junichirou Ohzeki
- Laboratory of Chromosome Engineering, Department of Frontier Research and Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu 292-0818, Japan
| | - Vladimir Larionov
- Genome Structure and Function Group, Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Hiroshi Masumoto
- Laboratory of Chromosome Engineering, Department of Frontier Research and Development, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu 292-0818, Japan.
| |
Collapse
|
17
|
Talbert PB, Henikoff S. Transcribing Centromeres: Noncoding RNAs and Kinetochore Assembly. Trends Genet 2018; 34:587-599. [DOI: 10.1016/j.tig.2018.05.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/08/2018] [Accepted: 05/09/2018] [Indexed: 12/20/2022]
|