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Shen K, Qu M, Zhao P. The Roads to Haploid Embryogenesis. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12020243. [PMID: 36678955 PMCID: PMC9865920 DOI: 10.3390/plants12020243] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/19/2022] [Accepted: 12/30/2022] [Indexed: 05/31/2023]
Abstract
Although zygotic embryogenesis is usually studied in the field of seed biology, great attention has been paid to the methods used to generate haploid embryos due to their applications in crop breeding. These mainly include two methods for haploid embryogenesis: in vitro microspore embryogenesis and in vivo haploid embryogenesis. Although microspore culture systems and maize haploid induction systems were discovered in the 1960s, little is known about the molecular mechanisms underlying haploid formation. In recent years, major breakthroughs have been made in in vivo haploid induction systems, and several key factors, such as the matrilineal (MTL), baby boom (BBM), domain of unknown function 679 membrane protein (DMP), and egg cell-specific (ECS) that trigger in vivo haploid embryo production in both the crops and Arabidopsis models have been identified. The discovery of these haploid inducers indicates that haploid embryogenesis is highly related to gamete development, fertilization, and genome stability in ealry embryos. Here, based on recent efforts to identify key players in haploid embryogenesis and to understand its molecular mechanisms, we summarize the different paths to haploid embryogenesis, and we discuss the mechanisms of haploid generation and its potential applications in crop breeding. Although these haploid-inducing factors could assist egg cells in bypassing fertilization to initiate embryogenesis or trigger genome elimination in zygotes after fertilization to form haploid embryos, the fertilization of central cells to form endosperms is a prerequisite step for haploid formation. Deciphering the molecular and cellular mechanisms for haploid embryogenesis, increasing the haploid induction efficiency, and establishing haploid induction systems in other crops are critical for promoting the application of haploid technology in crop breeding, and these should be addressed in further studies.
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Affiliation(s)
- Kun Shen
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Mengxue Qu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Peng Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
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2
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Dong Q, Li F. Cell cycle control of kinetochore assembly. Nucleus 2022; 13:208-220. [PMID: 36037227 PMCID: PMC9427032 DOI: 10.1080/19491034.2022.2115246] [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: 10/28/2022] Open
Abstract
The kinetochore is a large proteinaceous structure assembled on the centromeres of chromosomes. The complex machinery links chromosomes to the mitotic spindle and is essential for accurate chromosome segregation during cell division. The kinetochore is composed of two submodules: the inner and outer kinetochore. The inner kinetochore is assembled on centromeric chromatin and persists with centromeres throughout the cell cycle. The outer kinetochore attaches microtubules to the inner kinetochore, and assembles only during mitosis. The review focuses on recent advances in our understanding of the mechanisms governing the proper assembly of the outer kinetochore during mitosis and highlights open questions for future investigation.
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Affiliation(s)
- Qianhua Dong
- Department of Biology, New York University, New York, NY, USA
| | - Fei Li
- Department of Biology, New York University, New York, NY, USA
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3
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Centromere Chromatin Dynamics at a Glance. EPIGENOMES 2022; 6:epigenomes6040039. [PMID: 36412794 PMCID: PMC9680212 DOI: 10.3390/epigenomes6040039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 10/27/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
The centromere is a specialized DNA locus that ensures the faithful segregation of chromosomes during cell division. It does so by directing the assembly of an essential proteinaceous structure called the kinetochore. The centromere identity is primarily epigenetically defined by a nucleosome containing an H3 variant called CENP-A as well as by the interplay of several factors such as differential chromatin organization driven by CENP-A and H2A.Z, centromere-associated proteins, and post-translational modifications. At the centromere, CENP-A is not just a driving force for kinetochore assembly but also modifies the structural and dynamic properties of the centromeric chromatin, resulting in a distinctive chromatin organization. An additional level of regulation of the centromeric chromatin conformation is provided by post-translational modifications of the histones in the CENP-A nucleosomes. Further, H2A.Z is present in the regions flanking the centromere for heterochromatinization. In this review, we focus on the above-mentioned factors to describe how they contribute to the organization of the centromeric chromatin: CENP-A at the core centromere, post-translational modifications that decorate CENP-A, and the variant H2A.Z.
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4
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Gonzalez PA, Nagy PD. The centromeric histone CenH3 is recruited into the tombusvirus replication organelles. PLoS Pathog 2022; 18:e1010653. [PMID: 35767596 PMCID: PMC9275711 DOI: 10.1371/journal.ppat.1010653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/12/2022] [Accepted: 06/07/2022] [Indexed: 11/19/2022] Open
Abstract
Tombusviruses, similar to other (+)RNA viruses, exploit the host cells by co-opting numerous host components and rewiring cellular pathways to build extensive virus-induced replication organelles (VROs) in the cytosol of the infected cells. Most molecular resources are suboptimal in susceptible cells and therefore, tomato bushy stunt virus (TBSV) drives intensive remodeling and subversion of many cellular processes. The authors discovered that the nuclear centromeric CenH3 histone variant (Cse4p in yeast, CENP-A in humans) plays a major role in tombusvirus replication in plants and in the yeast model host. We find that over-expression of CenH3 greatly interferes with tombusvirus replication, whereas mutation or knockdown of CenH3 enhances TBSV replication in yeast and plants. CenH3 binds to the viral RNA and acts as an RNA chaperone. Although these data support a restriction role of CenH3 in tombusvirus replication, we demonstrate that by partially sequestering CenH3 into VROs, TBSV indirectly alters selective gene expression of the host, leading to more abundant protein pool. This in turn helps TBSV to subvert pro-viral host factors into replication. We show this through the example of hypoxia factors, glycolytic and fermentation enzymes, which are exploited more efficiently by tombusviruses to produce abundant ATP locally within the VROs in infected cells. Altogether, we propose that subversion of CenH3/Cse4p from the nucleus into cytosolic VROs facilitates transcriptional changes in the cells, which ultimately leads to more efficient ATP generation in situ within VROs by the co-opted glycolytic enzymes to support the energy requirement of virus replication. In summary, CenH3 plays both pro-viral and restriction functions during tombusvirus replication. This is a surprising novel role for a nuclear histone variant in cytosolic RNA virus replication.
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Affiliation(s)
| | - Peter D. Nagy
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
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5
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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.
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6
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Barbosa AC, Xu Z, Karari K, Williams W, Hauf S, Brown WRA. Mutation and selection explain why many eukaryotic centromeric DNA sequences are often A + T rich. Nucleic Acids Res 2021; 50:579-596. [PMID: 34928384 PMCID: PMC8754631 DOI: 10.1093/nar/gkab1219] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 11/16/2021] [Accepted: 11/30/2021] [Indexed: 01/10/2023] Open
Abstract
We have used chromosome engineering to replace native centromeric DNA with different test sequences at native centromeres in two different strains of the fission yeast Schizosaccharomyces pombe and have discovered that A + T rich DNA, whether synthetic or of bacterial origin, will function as a centromere in this species. Using genome size as a surrogate for the inverse of effective population size (Ne) we also show that the relative A + T content of centromeric DNA scales with Ne across 43 animal, fungal and yeast (Opisthokonta) species. This suggests that in most of these species the A + T content of the centromeric DNA is determined by a balance between selection and mutation. Combining the experimental results and the evolutionary analyses allows us to conclude that A + T rich DNA of almost any sequence will function as a centromere in most Opisthokonta species. The fact that many G/C to A/T substitutions are unlikely to be selected against may contribute to the rapid evolution of centromeric DNA. We also show that a neo-centromere sequence is not simply a weak version of native centromeric DNA and suggest that neo-centromeres require factors either for their propagation or establishment in addition to those required by native centromeres.
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Affiliation(s)
- Anne C Barbosa
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, NG7 2UH, UK
| | - Zhengyao Xu
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, NG7 2UH, UK
| | - Kazhal Karari
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, NG7 2UH, UK
| | - Wendi Williams
- Virginia Tech, Department of Biological Sciences, Fralin Life Sciences Institute, 1015 Life Science Circle, Blacksburg, VA 24061, USA
| | - Silke Hauf
- Virginia Tech, Department of Biological Sciences, Fralin Life Sciences Institute, 1015 Life Science Circle, Blacksburg, VA 24061, USA
| | - William R A Brown
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, NG7 2UH, UK
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7
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Inhibition of polar actin assembly by astral microtubules is required for cytokinesis. Nat Commun 2021; 12:2409. [PMID: 33893302 PMCID: PMC8065111 DOI: 10.1038/s41467-021-22677-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 03/19/2021] [Indexed: 02/07/2023] Open
Abstract
During cytokinesis, the actin cytoskeleton is partitioned into two spatially distinct actin isoform specific networks: a β-actin network that generates the equatorial contractile ring, and a γ-actin network that localizes to the cell cortex. Here we demonstrate that the opposing regulation of the β- and γ-actin networks is required for successful cytokinesis. While activation of the formin DIAPH3 at the cytokinetic furrow underlies β-actin filament production, we show that the γ-actin network is specifically depleted at the cell poles through the localized deactivation of the formin DIAPH1. During anaphase, CLIP170 is delivered by astral microtubules and displaces IQGAP1 from DIAPH1, leading to formin autoinhibition, a decrease in cortical stiffness and localized membrane blebbing. The contemporaneous production of a β-actin contractile ring at the cell equator and loss of γ-actin from the poles is required to generate a stable cytokinetic furrow and for the completion of cell division. During cell division, the actin cytoskeletal network at both the equatorial contractile ring and cell cortex are known to play a role, but the regulation of γ-actin during cytokinesis is less well understood. Here, the authors show that recruitment of β-actin to the contractile ring and loss of γ-actin from the cell poles is required for completion of cell division.
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8
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Thu YM. How Not To Be in the Wrong Place at the Wrong Time: An Education Primer for Use with "Deposition of Centromeric Histone H3 Variant CENP-A/Cse4 into Chromatin Is Facilitated by Its C-Terminal Sumoylation". Genetics 2020; 216:333-342. [PMID: 33023931 PMCID: PMC7536858 DOI: 10.1534/genetics.120.303493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 08/04/2020] [Indexed: 11/18/2022] Open
Abstract
Recent work by Kentaro Ohkuni and colleagues exemplifies how a series of molecular mechanisms contribute to a cellular outcome-equal distribution of chromosomes. Failure to maintain structural and numerical integrity of chromosomes is one contributing factor in genetic diseases such as cancer. Specifically, the authors investigated molecular events surrounding centromeric histone H3 variant Cse4 deposition-a process important for chromosome segregation, using Saccharomyces cerevisiae as a model organism. This study illustrates an example of a post-translational modification-sumoylation-regulating a cellular process and the concept of genetic interactions (e.g, synthetic dosage lethality). Furthermore, the study highlights the importance of using diverse experimental approaches in answering a few key research questions. The authors used molecular biology techniques (e.g., qPCR), biochemical experiments (e.g., Ni-NTA/8His protein purification), as well as genetic approaches to understand the regulation of Cse4 At a big-picture level, the study reveals how genetic changes can lead to subsequent molecular and cellular changes.
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Affiliation(s)
- Yee Mon Thu
- Department of Biology and Biochemistry Program, Allegheny College, Meadville, Pennsylvania 16335
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9
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Kim S, Park J, Kim T, Lee JS. The functional study of human proteins using humanized yeast. J Microbiol 2020; 58:343-349. [PMID: 32342338 DOI: 10.1007/s12275-020-0136-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/13/2020] [Accepted: 04/13/2020] [Indexed: 12/18/2022]
Abstract
The functional and optimal expression of genes is crucial for survival of all living organisms. Numerous experiments and efforts have been performed to reveal the mechanisms required for the functional and optimal expression of human genes. The yeast Saccharomyces cerevisiae has evolved independently of humans for billions of years. Nevertheless, S. cerevisiae has many conserved genes and expression mechanisms that are similar to those in humans. Yeast is the most commonly used model organism for studying the function and expression mechanisms of human genes because it has a relatively simple genome structure, which is easy to manipulate. Many previous studies have focused on understanding the functions and mechanisms of human proteins using orthologous genes and biological systems of yeast. In this review, we mainly introduce two recent studies that replaced human genes and nucleosomes with those of yeast. Here, we suggest that, although yeast is a relatively small eukaryotic cell, its humanization is useful for the direct study of human proteins. In addition, yeast can be used as a model organism in a broader range of studies, including drug screening.
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Affiliation(s)
- Seho Kim
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Juhee Park
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Taekyung Kim
- Department of Biology Education, Pusan National University, Busan, 26241, Republic of Korea.
| | - Jung-Shin Lee
- Department of Molecular Bioscience, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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10
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Wang S, Jin W, Wang K. Centromere histone H3- and phospholipase-mediated haploid induction in plants. PLANT METHODS 2019; 15:42. [PMID: 31057661 PMCID: PMC6485145 DOI: 10.1186/s13007-019-0429-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 04/24/2019] [Indexed: 05/14/2023]
Abstract
Simple and consistent production of haploid is always an appealing pursuit for both crop breeders and researchers. Although diverse strategies have been developed to produce haploids over the past decades, most of them are applicable in only a limited number of plant species. In 2010, Ravi and Chan reported that haploid Arabidopsis thaliana plants can be efficiently induced through the introduction of a single genetic alteration in centromere histone H3 (CENH3). Subsequent studies demonstrated that haploids can be efficiently induced either through genetic engineering of CENH3 N-terminal tail or histone fold domain or by replacing CENH3 with an ortholog. The mutation of a pollen-specific phospholipase gene, MATRILINEAL (MTL) has been revealed to trigger the haploid induction (HI) in maize, which present another promising HI approach by the editing of MTL in plant. Here, we review the progress of the CENH3-medialed HI and propose a revised centromere-size model by suggesting a competitive loading process between wild-type and mutant CENH3 during HI. This model can explain both the findings of HI failure when wild-type and mutant CENH3 genes are coexpressed and the alien centromere loading of CENH3 in stable hybrids. In addition, we review the current understanding of MTL-mediated HI in plant. The conservation of CENH3 and MTL in plants indicates wide potential application for HI. We discuss the utility and potential of these two methods in crops by comparing their mechanisms and applications to date in plants. This review will promote the study and application of both CENH3- and MTL-mediated haploid induction in plants.
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Affiliation(s)
- Song Wang
- Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Weiwei Jin
- College of Agriculture, China Agricultural University, No. 2, Yuan Ming Yuan West Road, Haidian District, Beijing, 100193 China
| | - Kai Wang
- Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
- National Engineering Research Center of Sugarcane, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
- Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
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11
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Heterochromatin and RNAi regulate centromeres by protecting CENP-A from ubiquitin-mediated degradation. PLoS Genet 2018; 14:e1007572. [PMID: 30089114 PMCID: PMC6101405 DOI: 10.1371/journal.pgen.1007572] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 08/20/2018] [Accepted: 07/18/2018] [Indexed: 01/03/2023] Open
Abstract
Centromere is a specialized chromatin domain that plays a vital role in chromosome segregation. In most eukaryotes, centromere is surrounded by the epigenetically distinct heterochromatin domain. Heterochromatin has been shown to contribute to centromere function, but the precise role of heterochromatin in centromere specification remains elusive. Centromeres in most eukaryotes, including fission yeast (Schizosaccharomyces pombe), are defined epigenetically by the histone H3 (H3) variant CENP-A. In contrast, the budding yeast Saccharomyces cerevisiae has genetically-defined point centromeres. The transition between regional centromeres and point centromeres is considered as one of the most dramatic evolutionary events in centromere evolution. Here we demonstrated that Cse4, the budding yeast CENP-A homolog, can localize to centromeres in fission yeast and partially substitute fission yeast CENP-ACnp1. But overexpression of Cse4 results in its localization to heterochromatic regions. Cse4 is subject to efficient ubiquitin-dependent degradation in S. pombe, and its N-terminal domain dictates its centromere distribution via ubiquitination. Notably, without heterochromatin and RNA interference (RNAi), Cse4 fails to associate with centromeres. We showed that RNAi-dependent heterochromatin mediates centromeric localization of Cse4 by protecting Cse4 from ubiquitin-dependent degradation. Heterochromatin also contributes to the association of native CENP-ACnp1 with centromeres via the same mechanism. These findings suggest that protection of CENP-A from degradation by heterochromatin is a general mechanism used for centromere assembly, and also provide novel insights into centromere evolution.
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12
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A Genome-Wide Screen Reveals a Role for the HIR Histone Chaperone Complex in Preventing Mislocalization of Budding Yeast CENP-A. Genetics 2018; 210:203-218. [PMID: 30012561 DOI: 10.1534/genetics.118.301305] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/12/2018] [Indexed: 11/18/2022] Open
Abstract
Centromeric localization of the evolutionarily conserved centromere-specific histone H3 variant CENP-A (Cse4 in yeast) is essential for faithful chromosome segregation. Overexpression and mislocalization of CENP-A lead to chromosome segregation defects in yeast, flies, and human cells. Overexpression of CENP-A has been observed in human cancers; however, the molecular mechanisms preventing CENP-A mislocalization are not fully understood. Here, we used a genome-wide synthetic genetic array (SGA) to identify gene deletions that exhibit synthetic dosage lethality (SDL) when Cse4 is overexpressed. Deletion for genes encoding the replication-independent histone chaperone HIR complex (HIR1, HIR2, HIR3, HPC2) and a Cse4-specific E3 ubiquitin ligase, PSH1, showed highest SDL. We defined a role for Hir2 in proteolysis of Cse4 that prevents mislocalization of Cse4 to noncentromeric regions for genome stability. Hir2 interacts with Cse4 in vivo, and hir2∆ strains exhibit defects in Cse4 proteolysis and stabilization of chromatin-bound Cse4 Mislocalization of Cse4 to noncentromeric regions with a preferential enrichment at promoter regions was observed in hir2∆ strains. We determined that Hir2 facilitates the interaction of Cse4 with Psh1, and that defects in Psh1-mediated proteolysis contribute to increased Cse4 stability and mislocalization of Cse4 in the hir2∆ strain. In summary, our genome-wide screen provides insights into pathways that regulate proteolysis of Cse4 and defines a novel role for the HIR complex in preventing mislocalization of Cse4 by facilitating proteolysis of Cse4, thereby promoting genome stability.
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13
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Hoischen C, Yavas S, Wohland T, Diekmann S. CENP-C/H/I/K/M/T/W/N/L and hMis12 but not CENP-S/X participate in complex formation in the nucleoplasm of living human interphase cells outside centromeres. PLoS One 2018; 13:e0192572. [PMID: 29509805 PMCID: PMC5839545 DOI: 10.1371/journal.pone.0192572] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 01/25/2018] [Indexed: 12/25/2022] Open
Abstract
Kinetochore proteins assemble onto centromeric chromatin and regulate DNA segregation during cell division. The inner kinetochore proteins bind centromeres while most outer kinetochore proteins assemble at centromeres during mitosis, connecting the complex to microtubules. Here, we measured the co-migration between protein pairs of the constitutive centromere associated network (CCAN) and hMis12 complexes by fluorescence cross-correlation spectroscopy (FCCS) in the nucleoplasm outside centromeres in living human interphase cells. FCCS is a method that can tell if in living cells two differently fluorescently labelled molecules migrate independently, or co-migrate and thus are part of one and the same soluble complex. We also determined the apparent dissociation constants (Kd) of the hetero-dimers CENP-T/W and CENP-S/X. We measured co-migration between CENP-K and CENP-T as well as between CENP-M and CENP-T but not between CENP-T/W and CENP-S/X. Furthermore, CENP-C co-migrated with CENP-H, and CENP-K with CENP-N as well as with CENP-L. Thus, in the nucleoplasm outside centromeres, a large fraction of the CENP-H/I/K/M proteins interact with CENP-C, CENP-N/L and CENP-T/W but not with CENP-S/X. Our FCCS analysis of the Mis12 complex showed that hMis12, Nsl1, Dsn1 and Nnf1 also form a complex outside centromeres of which at least hMis12 associated with the CENP-C/H/I/K/M/T/W/N/L complex.
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Affiliation(s)
- Christian Hoischen
- Molecular Biology, Leibniz Institute on Aging-Friz-Lipmann-Institute (FLI), Jena, Germany
| | - Sibel Yavas
- Departments of Biological Sciences and Chemistry and Centre of Bioimaging Sciences, Lee Wee Kheng Buildung, National University of Singapore, Singapore, Singapore
| | - Thorsten Wohland
- Departments of Biological Sciences and Chemistry and Centre of Bioimaging Sciences, Lee Wee Kheng Buildung, National University of Singapore, Singapore, Singapore
| | - Stephan Diekmann
- Molecular Biology, Leibniz Institute on Aging-Friz-Lipmann-Institute (FLI), Jena, Germany
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14
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A Failsafe for Sensing Chromatid Tension in Mitosis with the Histone H3 Tail in Saccharomyces cerevisiae. Genetics 2017; 208:565-578. [PMID: 29242290 DOI: 10.1534/genetics.117.300606] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 12/08/2017] [Indexed: 01/01/2023] Open
Abstract
Mitotic fidelity is ensured by achieving biorientation on all paired chromosomes. The key signal for proper chromosome alignment is the tension between sister chromatids created by opposing poleward force from the spindles. In the budding yeast, the tension-sensing function requires that the Shugoshin protein, Shugoshin 1, be recruited to the centromeres and the neighboring pericentric regions. Concerted actions integrating proteins at centromeres and pericentromeres create highly specific Shugoshin 1 domains on mitotic chromosomes. We have previously reported that an important regulatory region on histone H3, termed the tension-sensing motif (TSM), is responsible for retaining Shugoshin 1 at pericentromeres. The TSM is negatively regulated by the acetyltransferase Gcn5p, but the underlying mechanism was elusive. In this work, we provide evidence that, when the TSM function is impaired, the histone H3 tail adopts a role that complements the damaged TSM to ensure faithful mitosis. This novel function of the H3 tail is controlled by Gcn5p, which targets selective lysine residues. Mutations to K14 and K23 ameliorate the mitotic defects resulting from TSM mutations. The restoration of faithful segregation is accompanied by regaining Shugoshin 1 access to the pericentric regions. Our data reveal a novel pathway for mitotic Shugoshin 1 recruitment and further reinforce the active role played by chromatins during their segregation in mitosis.
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15
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Schalch T, Steiner FA. Structure of centromere chromatin: from nucleosome to chromosomal architecture. Chromosoma 2017; 126:443-455. [PMID: 27858158 PMCID: PMC5509776 DOI: 10.1007/s00412-016-0620-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/09/2016] [Accepted: 11/10/2016] [Indexed: 12/14/2022]
Abstract
The centromere is essential for the segregation of chromosomes, as it serves as attachment site for microtubules to mediate chromosome segregation during mitosis and meiosis. In most organisms, the centromere is restricted to one chromosomal region that appears as primary constriction on the condensed chromosome and is partitioned into two chromatin domains: The centromere core is characterized by the centromere-specific histone H3 variant CENP-A (also called cenH3) and is required for specifying the centromere and for building the kinetochore complex during mitosis. This core region is generally flanked by pericentric heterochromatin, characterized by nucleosomes containing H3 methylated on lysine 9 (H3K9me) that are bound by heterochromatin proteins. During mitosis, these two domains together form a three-dimensional structure that exposes CENP-A-containing chromatin to the surface for interaction with the kinetochore and microtubules. At the same time, this structure supports the tension generated during the segregation of sister chromatids to opposite poles. In this review, we discuss recent insight into the characteristics of the centromere, from the specialized chromatin structures at the centromere core and the pericentromere to the three-dimensional organization of these regions that make up the functional centromere.
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Affiliation(s)
- Thomas Schalch
- Department of Molecular Biology, Sciences III, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland.
| | - Florian A Steiner
- Department of Molecular Biology, Sciences III, Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland.
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16
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Maheshwari S, Ishii T, Brown CT, Houben A, Comai L. Centromere location in Arabidopsis is unaltered by extreme divergence in CENH3 protein sequence. Genome Res 2017; 27:471-478. [PMID: 28223399 PMCID: PMC5340974 DOI: 10.1101/gr.214619.116] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 12/14/2016] [Indexed: 12/17/2022]
Abstract
During cell division, spindle fibers attach to chromosomes at centromeres. The DNA sequence at regional centromeres is fast evolving with no conserved genetic signature for centromere identity. Instead CENH3, a centromere-specific histone H3 variant, is the epigenetic signature that specifies centromere location across both plant and animal kingdoms. Paradoxically, CENH3 is also adaptively evolving. An ongoing question is whether CENH3 evolution is driven by a functional relationship with the underlying DNA sequence. Here, we demonstrate that despite extensive protein sequence divergence, CENH3 histones from distant species assemble centromeres on the same underlying DNA sequence. We first characterized the organization and diversity of centromere repeats in wild-type Arabidopsis thaliana. We show that A. thaliana CENH3-containing nucleosomes exhibit a strong preference for a unique subset of centromeric repeats. These sequences are largely missing from the genome assemblies and represent the youngest and most homogeneous class of repeats. Next, we tested the evolutionary specificity of this interaction in a background in which the native A. thaliana CENH3 is replaced with CENH3s from distant species. Strikingly, we find that CENH3 from Lepidium oleraceum and Zea mays, although specifying epigenetically weaker centromeres that result in genome elimination upon outcrossing, show a binding pattern on A. thaliana centromere repeats that is indistinguishable from the native CENH3. Our results demonstrate positional stability of a highly diverged CENH3 on independently evolved repeats, suggesting that the sequence specificity of centromeres is determined by a mechanism independent of CENH3.
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Affiliation(s)
- Shamoni Maheshwari
- Plant Biology Department and Genome Center, University of California, Davis, California 95616, USA
| | - Takayoshi Ishii
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Stadt Seeland, Germany
| | - C Titus Brown
- Department of Population Health and Reproduction, University of California, Davis, California 95616, USA
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, 06466 Stadt Seeland, Germany
| | - Luca Comai
- Plant Biology Department and Genome Center, University of California, Davis, California 95616, USA
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17
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Vlijm R, Kim SH, De Zwart PL, Dalal Y, Dekker C. The supercoiling state of DNA determines the handedness of both H3 and CENP-A nucleosomes. NANOSCALE 2017; 9:1862-1870. [PMID: 28094382 PMCID: PMC7959483 DOI: 10.1039/c6nr06245h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Nucleosomes form the unit structure of the genome in eukaryotes, thereby constituting a fundamental tenet of chromatin biology. In canonical nucleosomes, DNA wraps around the histone octamer in a left-handed toroidal ramp. Here, in single-molecule magnetic tweezers studies of chaperone-assisted nucleosome assembly, we show that the handedness of the DNA wrapping around the nucleosome core is intrinsically ambidextrous, and depends on the pre-assembly supercoiling state of the DNA, i.e., it is not uniquely determined by the octameric histone core. Nucleosomes assembled onto negatively supercoiled DNA are found to exhibit a left-handed conformation, whereas assembly onto positively supercoiled DNA results in right-handed nucleosomes. This intrinsic flexibility to adopt both chiralities is observed both for canonical H3 nucleosomes, and for centromere-specific variant CENP-A nucleosomes. These data support recent advances suggesting an intrinsic adaptability of the nucleosome, and provide insights into how nucleosomes might rapidly re-assemble after cellular processes that generate positive supercoiling in vivo.
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Affiliation(s)
- R Vlijm
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, 2628CJ, The Netherlands
| | - S H Kim
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, 2628CJ, The Netherlands
| | - P L De Zwart
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, 2628CJ, The Netherlands
| | - Y Dalal
- Chromatin Structure and Epigenetic Mechanisms Unit, Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
| | - C Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, 2628CJ, The Netherlands
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18
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Abstract
Centromeric chromatin undergoes major changes in composition and architecture during each cell cycle. These changes in specialized chromatin facilitate kinetochore formation in mitosis to ensure proper chromosome segregation. Thus, proper orchestration of centromeric chromatin dynamics during interphase, including replication in S phase, is crucial. We provide the current view concerning the centromeric architecture associated with satellite repeat sequences in mammals and its dynamics during the cell cycle. We summarize the contributions of deposited histone variants and their chaperones, other centromeric components - including proteins and their post-translational modifications, and RNAs - and we link the expression and deposition timing of each component during the cell cycle. Because neocentromeres occur at ectopic sites, we highlight how cell cycle processes can go wrong, leading to neocentromere formation and potentially disease.
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Affiliation(s)
- Sebastian Müller
- Institut Curie, PSL Research University, CNRS, UMR3664, Equipe Labellisée Ligue contre le Cancer, F-75005 Paris, France.,Sorbonne Universités, UPMC Université Paris 06, CNRS, UMR3664, F-75005 Paris, France
| | - Geneviève Almouzni
- Institut Curie, PSL Research University, CNRS, UMR3664, Equipe Labellisée Ligue contre le Cancer, F-75005 Paris, France.,Sorbonne Universités, UPMC Université Paris 06, CNRS, UMR3664, F-75005 Paris, France
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19
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Co-evolving CENP-A and CAL1 Domains Mediate Centromeric CENP-A Deposition across Drosophila Species. Dev Cell 2016; 37:136-47. [PMID: 27093083 DOI: 10.1016/j.devcel.2016.03.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 03/04/2016] [Accepted: 03/22/2016] [Indexed: 11/20/2022]
Abstract
Centromeres mediate the conserved process of chromosome segregation, yet centromeric DNA and the centromeric histone, CENP-A, are rapidly evolving. The rapid evolution of Drosophila CENP-A loop 1 (L1) is thought to modulate the DNA-binding preferences of CENP-A to counteract centromere drive, the preferential transmission of chromosomes with expanded centromeric satellites. Consistent with this model, CENP-A from Drosophila bipectinata (bip) cannot localize to Drosophila melanogaster (mel) centromeres. We show that this result is due to the inability of the mel CENP-A chaperone, CAL1, to deposit bip CENP-A into chromatin. Co-expression of bip CENP-A and bip CAL1 in mel cells restores centromeric localization, and similar findings apply to other Drosophila species. We identify two co-evolving regions, CENP-A L1 and the CAL1 N terminus, as critical for lineage-specific CENP-A incorporation. Collectively, our data show that the rapid evolution of L1 modulates CAL1-mediated CENP-A assembly, suggesting an alternative mechanism for the suppression of centromere drive.
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20
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Zasadzińska E, Foltz DR. Centromeres of a Different CAL-ibre. Dev Cell 2016; 37:105-6. [PMID: 27093076 DOI: 10.1016/j.devcel.2016.04.006] [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] [Indexed: 11/18/2022]
Abstract
Centromeres of higher eukaryotes are defined by the epigenetic inheritance of the centromere-specific CENP-A nucleosome. Reporting in Developmental Cell, Rosin and Mellone (2016) show that co-evolution of the CENP-A histone variant and its chaperone CAL1 accounts for species incompatibility between centromeric histones in Drosophila.
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Affiliation(s)
- Ewelina Zasadzińska
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Daniel R Foltz
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Biochemistry and Molecular Genetics, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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21
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Ohkuni K, Takahashi Y, Fulp A, Lawrimore J, Au WC, Pasupala N, Levy-Myers R, Warren J, Strunnikov A, Baker RE, Kerscher O, Bloom K, Basrai MA. SUMO-Targeted Ubiquitin Ligase (STUbL) Slx5 regulates proteolysis of centromeric histone H3 variant Cse4 and prevents its mislocalization to euchromatin. Mol Biol Cell 2016; 27:mbc.E15-12-0827. [PMID: 26960795 PMCID: PMC4850037 DOI: 10.1091/mbc.e15-12-0827] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/17/2016] [Accepted: 03/03/2016] [Indexed: 12/14/2022] Open
Abstract
Centromeric histone H3, CENP-ACse4, is essential for faithful chromosome segregation. Stringent regulation of cellular levels of CENP-ACse4 restricts its localization to centromeres. Mislocalization of CENP-ACse4 is associated with aneuploidy in yeast, flies and tumorigenesis in human cells; thus, defining pathways that regulate CENP-A levels is critical for understanding how mislocalization of CENP-A contributes to aneuploidy in human cancers. Previous work in budding yeast has shown that ubiquitination of overexpressed Cse4 by Psh1, an E3 ligase, partially contributes to proteolysis of Cse4. Here, we provide the first evidence that Cse4 is sumoylated by E3 ligases Siz1 and Siz2 in vivo and in vitro. Ubiquitination of Cse4 by Small Ubiquitin-related Modifier (SUMO)-Targeted Ubiquitin Ligase (STUbL) Slx5 plays a critical role in proteolysis of Cse4 and prevents mislocalization of Cse4 to euchromatin under normal physiological conditions. Accumulation of sumoylated Cse4 species and increased stability of Cse4 in slx5∆ strains suggest that sumoylation precedes ubiquitin-mediated proteolysis of Cse4. Slx5-mediated Cse4 proteolysis is independent of Psh1 since slx5∆ psh1∆ strains exhibit higher levels of Cse4 stability and mislocalization compared to either slx5∆ or psh1∆ strains. Our results demonstrate a role for Slx5 in ubiquitin-mediated proteolysis of Cse4 to prevent its mislocalization and maintain genome stability.
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Affiliation(s)
- Kentaro Ohkuni
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Yoshimitsu Takahashi
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Alyona Fulp
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Josh Lawrimore
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Wei-Chun Au
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Nagesh Pasupala
- Biology Department, The College of William & Mary, Williamsburg, VA 23187
| | - Reuben Levy-Myers
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
- Biology Department, The College of William & Mary, Williamsburg, VA 23187
| | - Jack Warren
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | | | - Richard E. Baker
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655
| | - Oliver Kerscher
- Biology Department, The College of William & Mary, Williamsburg, VA 23187
| | - Kerry Bloom
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Munira A. Basrai
- Genetics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
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22
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Tame MA, Raaijmakers JA, Afanasyev P, Medema RH. Chromosome misalignments induce spindle-positioning defects. EMBO Rep 2016; 17:317-25. [PMID: 26882550 PMCID: PMC4772978 DOI: 10.15252/embr.201541143] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 12/08/2015] [Accepted: 01/04/2016] [Indexed: 11/09/2022] Open
Abstract
Cortical pulling forces on astral microtubules are essential to position the spindle. These forces are generated by cortical dynein, a minus-end directed motor. Previously, another dynein regulator termed Spindly was proposed to regulate dynein-dependent spindle positioning. However, the mechanism of how Spindly regulates spindle positioning has remained elusive. Here, we find that the misalignment of chromosomes caused by Spindly depletion is directly provoking spindle misorientation. Chromosome misalignments induced by CLIP-170 or CENP-E depletion or by noscapine treatment are similarly accompanied by severe spindle-positioning defects. We find that cortical LGN is actively displaced from the cortex when misaligned chromosomes are in close proximity. Preventing the KT recruitment of Plk1 by the depletion of PBIP1 rescues cortical LGN enrichment near misaligned chromosomes and re-establishes proper spindle orientation. Hence, KT-enriched Plk1 is responsible for the negative regulation of cortical LGN localization. In summary, we uncovered a compelling molecular link between chromosome alignment and spindle orientation defects, both of which are implicated in tumorigenesis.
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Affiliation(s)
- Mihoko A Tame
- Department of Cell Biology and Cancer Genomics Center, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Jonne A Raaijmakers
- Department of Cell Biology and Cancer Genomics Center, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Pavel Afanasyev
- The Maastricht Multimodal Molecular Imaging Institute, Maastricht University, Maastricht, The Netherlands
| | - René H Medema
- Department of Cell Biology and Cancer Genomics Center, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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23
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Schmoll M, Dattenböck C, Carreras-Villaseñor N, Mendoza-Mendoza A, Tisch D, Alemán MI, Baker SE, Brown C, Cervantes-Badillo MG, Cetz-Chel J, Cristobal-Mondragon GR, Delaye L, Esquivel-Naranjo EU, Frischmann A, Gallardo-Negrete JDJ, García-Esquivel M, Gomez-Rodriguez EY, Greenwood DR, Hernández-Oñate M, Kruszewska JS, Lawry R, Mora-Montes HM, Muñoz-Centeno T, Nieto-Jacobo MF, Nogueira Lopez G, Olmedo-Monfil V, Osorio-Concepcion M, Piłsyk S, Pomraning KR, Rodriguez-Iglesias A, Rosales-Saavedra MT, Sánchez-Arreguín JA, Seidl-Seiboth V, Stewart A, Uresti-Rivera EE, Wang CL, Wang TF, Zeilinger S, Casas-Flores S, Herrera-Estrella A. The Genomes of Three Uneven Siblings: Footprints of the Lifestyles of Three Trichoderma Species. Microbiol Mol Biol Rev 2016; 80:205-327. [PMID: 26864432 PMCID: PMC4771370 DOI: 10.1128/mmbr.00040-15] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The genus Trichoderma contains fungi with high relevance for humans, with applications in enzyme production for plant cell wall degradation and use in biocontrol. Here, we provide a broad, comprehensive overview of the genomic content of these species for "hot topic" research aspects, including CAZymes, transport, transcription factors, and development, along with a detailed analysis and annotation of less-studied topics, such as signal transduction, genome integrity, chromatin, photobiology, or lipid, sulfur, and nitrogen metabolism in T. reesei, T. atroviride, and T. virens, and we open up new perspectives to those topics discussed previously. In total, we covered more than 2,000 of the predicted 9,000 to 11,000 genes of each Trichoderma species discussed, which is >20% of the respective gene content. Additionally, we considered available transcriptome data for the annotated genes. Highlights of our analyses include overall carbohydrate cleavage preferences due to the different genomic contents and regulation of the respective genes. We found light regulation of many sulfur metabolic genes. Additionally, a new Golgi 1,2-mannosidase likely involved in N-linked glycosylation was detected, as were indications for the ability of Trichoderma spp. to generate hybrid galactose-containing N-linked glycans. The genomic inventory of effector proteins revealed numerous compounds unique to Trichoderma, and these warrant further investigation. We found interesting expansions in the Trichoderma genus in several signaling pathways, such as G-protein-coupled receptors, RAS GTPases, and casein kinases. A particularly interesting feature absolutely unique to T. atroviride is the duplication of the alternative sulfur amino acid synthesis pathway.
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Affiliation(s)
- Monika Schmoll
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | - Christoph Dattenböck
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | | | | | - Doris Tisch
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | - Mario Ivan Alemán
- Cinvestav, Department of Genetic Engineering, Irapuato, Guanajuato, Mexico
| | - Scott E Baker
- Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Christopher Brown
- University of Otago, Department of Biochemistry and Genetics, Dunedin, New Zealand
| | | | - José Cetz-Chel
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | | | - Luis Delaye
- Cinvestav, Department of Genetic Engineering, Irapuato, Guanajuato, Mexico
| | | | - Alexa Frischmann
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | | | - Monica García-Esquivel
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | | | - David R Greenwood
- The University of Auckland, School of Biological Sciences, Auckland, New Zealand
| | - Miguel Hernández-Oñate
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
| | - Joanna S Kruszewska
- Polish Academy of Sciences, Institute of Biochemistry and Biophysics, Laboratory of Fungal Glycobiology, Warsaw, Poland
| | - Robert Lawry
- Lincoln University, Bio-Protection Research Centre, Lincoln, Canterbury, New Zealand
| | | | | | | | | | | | | | - Sebastian Piłsyk
- Polish Academy of Sciences, Institute of Biochemistry and Biophysics, Laboratory of Fungal Glycobiology, Warsaw, Poland
| | - Kyle R Pomraning
- Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Aroa Rodriguez-Iglesias
- Austrian Institute of Technology, Department Health and Environment, Bioresources Unit, Tulln, Austria
| | | | | | - Verena Seidl-Seiboth
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria
| | | | | | - Chih-Li Wang
- National Chung-Hsing University, Department of Plant Pathology, Taichung, Taiwan
| | - Ting-Fang Wang
- Academia Sinica, Institute of Molecular Biology, Taipei, Taiwan
| | - Susanne Zeilinger
- Research Division Biotechnology and Microbiology, Institute of Chemical Engineering, TU Wien, Vienna, Austria University of Innsbruck, Institute of Microbiology, Innsbruck, Austria
| | | | - Alfredo Herrera-Estrella
- LANGEBIO, National Laboratory of Genomics for Biodiversity, Cinvestav-Irapuato, Guanajuato, Mexico
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Britt AB, Kuppu S. Cenh3: An Emerging Player in Haploid Induction Technology. FRONTIERS IN PLANT SCIENCE 2016; 7:357. [PMID: 27148276 PMCID: PMC4828581 DOI: 10.3389/fpls.2016.00357] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 03/07/2016] [Indexed: 05/18/2023]
Abstract
True-breeding lines are required for the development and production of crop varieties. In a classical breeding approach these lines are obtained through inbreeding, and often 7-9 generations of inbreeding is performed to achieve the desired level of homozygosity, over a period of several years. In contrast, the chromosomes of haploids can be doubled to produce true-breeding lines in a single generation. Over the last century, scientists have developed a variety of techniques to induce haploids and doubled haploids, though these techniques apply only to particular crop varieties. Ravi and Chan (2010) discovered that haploids could be obtained in Arabidopsis through the manipulation of the centromere-specific histone 3 variant, CENH3. Their approach, which involved extensive modifications to a transgenic CENH3, held promise of being translated to crop species, and has been successfully employed in maize (see Kelliher et al., 2016). Refinements of this technology have since been developed which indicate that non-transgenic modifications to CENH3 will also induce haploids. The complementation of a cenh3 null by CENH3 from closely related plant species can result in plants that are fertile but haploid-inducing on crossing by CENH3 wt plants- suggesting that introgression of alien CENH3 may produce non-transgenic haploid inducers. Similarly, a remarkably wide variety of point mutations in CENH3, inducible by chemical agents, have recently been shown to result in haploid induction on crossing by wild-type CENH3 plants. These CENH3-variant plants grow normally, are fully fertile on self-pollination, and may be present in existing mutagenized collections.
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25
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Depletion of UBC9 Causes Nuclear Defects during the Vegetative and Sexual Life Cycles in Tetrahymena thermophila. EUKARYOTIC CELL 2015; 14:1240-52. [PMID: 26453653 DOI: 10.1128/ec.00115-15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 10/03/2015] [Indexed: 11/20/2022]
Abstract
Ubc9p is the sole E2-conjugating enzyme for SUMOylation, and its proper function is required for regulating key nuclear events such as transcription, DNA repair, and mitosis. In Tetrahymena thermophila, the genome is separated into a diploid germ line micronucleus (MIC) that divides by mitosis and a polyploid somatic macronucleus (MAC) that divides amitotically. This unusual nuclear organization provides novel opportunities for the study of SUMOylation and Ubc9p function. We identified the UBC9 gene and demonstrated that its complete deletion from both MIC and MAC genomes is lethal. Rescue of the lethal phenotype with a GFP-UBC9 fusion gene driven by a metallothionein promoter generated a cell line with CdCl2-dependent expression of green fluorescent protein (GFP)-Ubc9p. Depletion of Ubc9p in vegetative cells resulted in the loss of MICs, but MACs continued to divide. In contrast, expression of catalytically inactive Ubc9p resulted in the accumulation of multiple MICs. Critical roles for Ubc9p were also identified during the sexual life cycle of Tetrahymena. Cell lines that were depleted for Ubc9p did not form mating pairs and therefore could not complete any of the subsequent stages of conjugation, including meiosis and macronuclear development. Mating between cells expressing catalytically inactive Ubc9p resulted in arrest during macronuclear development, consistent with our observation that Ubc9p accumulates in the developing macronucleus.
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26
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Amin MA, Kobayashi K, Tanaka K. CLIP-170 tethers kinetochores to microtubule plus ends against poleward force by dynein for stable kinetochore-microtubule attachment. FEBS Lett 2015; 589:2739-46. [PMID: 26231764 DOI: 10.1016/j.febslet.2015.07.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 07/17/2015] [Indexed: 12/21/2022]
Abstract
The cytoplasmic linker protein (CLIP)-170 localizes to kinetochores and is suggested to function in stable attachment of kinetochores to microtubule ends. Here we show that defects in kinetochore-microtubule attachment and chromosome alignment in CLIP-170-depleted cells were rescued by co-depletion of p150glued, a dynactin subunit required for kinetochore localization of CLIP-170. CLIP-170 recruited p150glued to microtubule ends. Kinetochore localization at microtubule ends was perturbed by CLIP-170 depletion, which was rescued by co-depleting p150glued. Our results imply that CLIP-170 tethers kinetochores to microtubule ends against the dynein-mediated poleward force to slide kinetochores along microtubules, facilitating the stable kinetochore attachment to microtubules.
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Affiliation(s)
- Mohammed Abdullahel Amin
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan.
| | - Kinue Kobayashi
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan
| | - Kozo Tanaka
- Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan.
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27
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Steiner FA, Henikoff S. Diversity in the organization of centromeric chromatin. Curr Opin Genet Dev 2015; 31:28-35. [PMID: 25956076 DOI: 10.1016/j.gde.2015.03.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 03/26/2015] [Accepted: 03/28/2015] [Indexed: 01/15/2023]
Abstract
Centromeric chromatin is distinguished primarily by nucleosomes containing the histone variant cenH3, which organizes the kinetochore that links the chromosome to the spindle apparatus. Whereas budding yeast have simple 'point' centromeres with single cenH3 nucleosomes, and fission yeast have 'regional' centromeres without obvious sequence specificity, the centromeres of most organisms are embedded in highly repetitive 'satellite' DNA. Recent studies have revealed a remarkable diversity in centromere chromatin organization among different lineages, including some that have lost cenH3 altogether. We review recent progress in understanding point, regional and satellite centromeres, as well as less well-studied centromere types, such as holocentromeres. We also discuss the formation of neocentromeres, the role of pericentric heterochromatin, and the structure and composition of the cenH3 nucleosome.
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Affiliation(s)
- Florian A Steiner
- Basic Sciences Division and Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Steven Henikoff
- Basic Sciences Division and Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
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28
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Abendroth C, Hofmeister A, Hake SB, Kamweru PK, Miess E, Dornblut C, Küffner I, Deng W, Leonhardt H, Orthaus S, Hoischen C, Diekmann S. The CENP-T C-terminus is exclusively proximal to H3.1 and not to H3.2 or H3.3. Int J Mol Sci 2015; 16:5839-63. [PMID: 25775162 PMCID: PMC4394509 DOI: 10.3390/ijms16035839] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 02/18/2015] [Accepted: 02/18/2015] [Indexed: 12/17/2022] Open
Abstract
The kinetochore proteins assemble onto centromeric chromatin and regulate DNA segregation during cell division. The inner kinetochore proteins bind centromeres while most outer kinetochore proteins assemble at centromeres during mitosis, connecting the complex to microtubules. The centromere-kinetochore complex contains specific nucleosomes and nucleosomal particles. CENP-A replaces canonical H3 in centromeric nucleosomes, defining centromeric chromatin. Next to CENP-A, the CCAN multi-protein complex settles which contains CENP-T/W/S/X. These four proteins are described to form a nucleosomal particle at centromeres. We had found the CENP-T C-terminus and the CENP-S termini next to histone H3.1 but not to CENP-A, suggesting that the Constitutive Centromere-Associated Network (CCAN) bridges a CENP-A- and a H3-containing nucleosome. Here, we show by in vivo FRET that this proximity between CENP-T and H3 is specific for H3.1 but neither for the H3.1 mutants H3.1(C96A) and H3.1(C110A) nor for H3.2 or H3.3. We also found CENP-M next to H3.1 but not to these H3.1 mutants. Consistently, we detected CENP-M next to CENP-S. These data elucidate the local molecular neighborhood of CCAN proteins next to a H3.1-containing centromeric nucleosome. They also indicate an exclusive position of H3.1 clearly distinct from H3.2, thus documenting a local, and potentially also functional, difference between H3.1 and H3.2.
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Affiliation(s)
- Christian Abendroth
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Antje Hofmeister
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Sandra B Hake
- Department of Molecular Biology, Center for Integrated Protein Science Munich (CIPSM), Adolf-Butenandt-Institute, Ludwig-Maximilians-Universität Munich, Schillerstr. 44, D-80336 Munich, Germany.
| | - Paul K Kamweru
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Elke Miess
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Carsten Dornblut
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Isabell Küffner
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Wen Deng
- Department of Biology II, Center for Integrated Protein Science, Ludwig-Maximilians-Universität Munich, Planegg-Martinsried, D-82152 Munich, Germany.
| | - Heinrich Leonhardt
- Department of Biology II, Center for Integrated Protein Science, Ludwig-Maximilians-Universität Munich, Planegg-Martinsried, D-82152 Munich, Germany.
| | | | - Christian Hoischen
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
| | - Stephan Diekmann
- Molecular Biology, Fritz Lipmann Institute, Beutenbergstr. 11, D-07745 Jena, Germany.
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Abstract
The centromere-the primary constriction of monocentric chromosomes-is essential for correct segregation of chromosomes during mitosis and meiosis. Centromeric DNA varies between different organisms in sequence composition and extension. The main components of centromeric and pericentromeric DNA of Brassicaceae species are centromeric satellite repeats. Centromeric DNA initiates assembly of the kinetochore, the large protein complex where the spindle fibers attach during nuclear division to pull sister chromatids apart. Kinetochore assembly is initiated by incorporation of the centromeric histone H3 cenH3 into centromeric nucleosomes. The spindle assembly checkpoint acts during mitosis and meiosis at centromeres and maintains genome stability by preventing chromosome segregation before all kinetochores are correctly attached to microtubules. The function of the spindle assembly checkpoint in plants is still poorly understood. Here, we review recent advances of studies on structure and functional importance of centromeric DNA of Brassicaceae, assembly and function of cenH3 in Arabidopsis thaliana and characterization of core SAC proteins of A. thaliana in comparison with non-plant homologues.
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Affiliation(s)
- Inna Lermontova
- Leibniz Institute of Plant Genetics and Crop Plant Research, 06466, Gatersleben, Germany,
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30
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Maheshwari S, Tan EH, West A, Franklin FCH, Comai L, Chan SWL. Naturally occurring differences in CENH3 affect chromosome segregation in zygotic mitosis of hybrids. PLoS Genet 2015; 11:e1004970. [PMID: 25622028 PMCID: PMC4314295 DOI: 10.1371/journal.pgen.1004970] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 12/20/2014] [Indexed: 11/19/2022] Open
Abstract
The point of attachment of spindle microtubules to metaphase chromosomes is known as the centromere. Plant and animal centromeres are epigenetically specified by a centromere-specific variant of Histone H3, CENH3 (a.k.a. CENP-A). Unlike canonical histones that are invariant, CENH3 proteins are accumulating substitutions at an accelerated rate. This diversification of CENH3 is a conundrum since its role as the key determinant of centromere identity remains a constant across species. Here, we ask whether naturally occurring divergence in CENH3 has functional consequences. We performed functional complementation assays on cenh3-1, a null mutation in Arabidopsis thaliana, using untagged CENH3s from increasingly distant relatives. Contrary to previous results using GFP-tagged CENH3, we find that the essential functions of CENH3 are conserved across a broad evolutionary landscape. CENH3 from a species as distant as the monocot Zea mays can functionally replace A. thaliana CENH3. Plants expressing variant CENH3s that are fertile when selfed show dramatic segregation errors when crossed to a wild-type individual. The progeny of this cross include hybrid diploids, aneuploids with novel genetic rearrangements and haploids that inherit only the genome of the wild-type parent. Importantly, it is always chromosomes from the plant expressing the divergent CENH3 that missegregate. Using chimeras, we show that it is divergence in the fast-evolving N-terminal tail of CENH3 that is causing segregation errors and genome elimination. Furthermore, we analyzed N-terminal tail sequences from plant CENH3s and discovered a modular pattern of sequence conservation. From this we hypothesize that while the essential functions of CENH3 are largely conserved, the N-terminal tail is evolving to adapt to lineage-specific centromeric constraints. Our results demonstrate that this lineage-specific evolution of CENH3 causes inviability and sterility of progeny in crosses, at the same time producing karyotypic variation. Thus, CENH3 evolution can contribute to postzygotic reproductive barriers.
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Affiliation(s)
- Shamoni Maheshwari
- Department of Plant Biology and Genome Center, University of California, Davis, Davis, California, United States of America
| | - Ek Han Tan
- Department of Plant Biology and Genome Center, University of California, Davis, Davis, California, United States of America
| | - Allan West
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - F. Chris H. Franklin
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Luca Comai
- Department of Plant Biology and Genome Center, University of California, Davis, Davis, California, United States of America
- * E-mail:
| | - Simon W. L. Chan
- Department of Plant Biology, University of California, Davis, Davis, California, United States of America
- Howard-Hughes Medical Institute and the Gordon and Betty Moore Foundation, University of California, Davis, Davis, California, United States of America
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31
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Abstract
Histones package and compact DNA by assembling into nucleosome core particles. Most histones are synthesized at S phase for rapid deposition behind replication forks. In addition, the replacement of histones deposited during S phase by variants that can be deposited independently of replication provide the most fundamental level of chromatin differentiation. Alternative mechanisms for depositing different variants can potentially establish and maintain epigenetic states. Variants have also evolved crucial roles in chromosome segregation, transcriptional regulation, DNA repair, and other processes. Investigations into the evolution, structure, and metabolism of histone variants provide a foundation for understanding the participation of chromatin in important cellular processes and in epigenetic memory.
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Affiliation(s)
- Steven Henikoff
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024
| | - M Mitchell Smith
- Department of Microbiology, University of Virginia, Charlottesville, Virginia 22908
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32
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Gao D, Jiang N, Wing RA, Jiang J, Jackson SA. Transposons play an important role in the evolution and diversification of centromeres among closely related species. FRONTIERS IN PLANT SCIENCE 2015; 6:216. [PMID: 25904926 PMCID: PMC4387472 DOI: 10.3389/fpls.2015.00216] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Accepted: 03/17/2015] [Indexed: 05/18/2023]
Abstract
Centromeres are important chromosomal regions necessary for eukaryotic cell segregation and replication. Due to high amounts of tandem repeats and transposons, centromeres have been difficult to sequence in most multicellular organisms, thus their sequence structure and evolution are poorly understood. In this study, we analyzed transposons in the centromere 8 (Cen8) from the African cultivated rice (O. glaberrima) and two subspecies of the Asian cultivated rice (O. sativa), indica and japonica. We detected much higher transposon contents (>69%) in centromere regions than in the whole genomes of O. sativa ssp. japonica and O. glaberrima (~35%). We compared the three Cen8s and identified numerous recent insertions of transposons that were frequently organized into multiple-layer nested blocks, similar to nested transposons in maize. Except for the Hopi retrotransposon, all LTR retrotransposons were shared but exhibit different abundances amongst the three Cen8s. Even though a majority of the transposons were located in intergenic regions, some gene-related transposons were found and may be involved in gene diversification. Chromatin immunoprecipitated (ChIP) data analysis revealed that 165 families from both Class I and Class II transposons were found in CENH3-associated chromatin sequences. These results indicate essential roles for transposons in centromeres and that the rapid divergence of the Cen8 sequences between the two cultivated rice species was primarily caused by recent transposon insertions.
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Affiliation(s)
- Dongying Gao
- Center for Applied Genetic Technologies, University of GeorgiaAthens, GA, USA
| | - Ning Jiang
- Department of Horticulture, Michigan State UniversityEast Lansing, MI, USA
| | - Rod A. Wing
- Department of Plant Sciences, Arizona Genome Institute, University of ArizonaTucson, AZ, USA
| | - Jiming Jiang
- Department of Horticulture, University of Wisconsin-MadisonMadison, WI, USA
| | - Scott A. Jackson
- Center for Applied Genetic Technologies, University of GeorgiaAthens, GA, USA
- *Correspondence: Scott A. Jackson, Center for Applied Genetic Technologies, University of Georgia, 111 Riverbend Rd, Athens, GA 30602, USA
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33
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Ho KH, Tsuchiya D, Oliger AC, Lacefield S. Localization and function of budding yeast CENP-A depends upon kinetochore protein interactions and is independent of canonical centromere sequence. Cell Rep 2014; 9:2027-33. [PMID: 25533342 DOI: 10.1016/j.celrep.2014.11.037] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 10/20/2014] [Accepted: 11/22/2014] [Indexed: 11/24/2022] Open
Abstract
In many eukaryotes, the centromere is epigenetically specified and not strictly defined by sequence. In contrast, budding yeast has a specific 125 bp sequence required for kinetochore function. Despite the difference in centromere specification, budding yeast and multicellular eukaryotic centromeres contain a highly conserved histone H3 variant, CENP-A. The localization of budding yeast CENP-A, Cse4, requires the centromere DNA binding components, which are not conserved in multicellular eukaryotes. Here, we report that Cse4 localizes and functions at a synthetic kinetochore assembly site that lacks centromere sequence. The outer kinetochore Dam1-DASH and inner kinetochore CBF3 complexes are required for Cse4 localization to that site. Furthermore, the natural kinetochore also requires the outer kinetochore proteins for full Cse4 localization. Our results suggest that Cse4 localization at a functional kinetochore does not require the recognition of a specific DNA sequence by the CBF3 complex; rather, its localization depends on stable interactions among kinetochore proteins.
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Affiliation(s)
- Kung-Hsien Ho
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Dai Tsuchiya
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Audrey C Oliger
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Soni Lacefield
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
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34
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Ferreira JG, Pereira AL, Maiato H. Microtubule plus-end tracking proteins and their roles in cell division. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 309:59-140. [PMID: 24529722 DOI: 10.1016/b978-0-12-800255-1.00002-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Microtubules are cellular components that are required for a variety of essential processes such as cell motility, mitosis, and intracellular transport. This is possible because of the inherent dynamic properties of microtubules. Many of these properties are tightly regulated by a number of microtubule plus-end-binding proteins or +TIPs. These proteins recognize the distal end of microtubules and are thus in the right context to control microtubule dynamics. In this review, we address how microtubule dynamics are regulated by different +TIP families, focusing on how functionally diverse +TIPs spatially and temporally regulate microtubule dynamics during animal cell division.
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Affiliation(s)
- Jorge G Ferreira
- Chromosome Instability & Dynamics Laboratory, Instituto de Biologia Molecular e Celular, University of Porto, Porto, Portugal; Cell Division Unit, Department of Experimental Biology, University of Porto, Porto, Portugal
| | - Ana L Pereira
- Chromosome Instability & Dynamics Laboratory, Instituto de Biologia Molecular e Celular, University of Porto, Porto, Portugal
| | - Helder Maiato
- Chromosome Instability & Dynamics Laboratory, Instituto de Biologia Molecular e Celular, University of Porto, Porto, Portugal; Cell Division Unit, Department of Experimental Biology, University of Porto, Porto, Portugal.
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35
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Selmansberger M, Feuchtinger A, Zurnadzhy L, Michna A, Kaiser JC, Abend M, Brenner A, Bogdanova T, Walch A, Unger K, Zitzelsberger H, Hess J. CLIP2 as radiation biomarker in papillary thyroid carcinoma. Oncogene 2014; 34:3917-25. [DOI: 10.1038/onc.2014.311] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 07/16/2014] [Accepted: 08/09/2014] [Indexed: 12/16/2022]
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36
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A network of players in H3 histone variant deposition and maintenance at centromeres. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:241-50. [DOI: 10.1016/j.bbagrm.2013.11.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 11/14/2013] [Accepted: 11/19/2013] [Indexed: 11/21/2022]
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37
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Biomolecular dynamics and binding studies in the living cell. Phys Life Rev 2014; 11:1-30. [DOI: 10.1016/j.plrev.2013.11.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 11/20/2013] [Indexed: 11/22/2022]
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38
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Verma G, Surolia N. Plasmodium falciparum CENH3 is able to functionally complement Cse4p and its, C-terminus is essential for centromere function. Mol Biochem Parasitol 2013; 192:21-9. [PMID: 24316361 DOI: 10.1016/j.molbiopara.2013.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 10/31/2013] [Accepted: 11/21/2013] [Indexed: 11/16/2022]
Abstract
The Plasmodium falciparum centromeric histone variant PfCENH3 has been shown to occupy a 4-4.5 kb region on each chromosome, but the experimental demonstration of its structure-function relationship remains unexplored. By functional complementation assays, we report that the C-terminus, specifically the CATD region within the HFD of PfCENH3 is essential in centromere function. Our studies also indicate that the PfCENH3 specific LLAL residues of the CATD region are required for centromere targeting and chromosome segregation. Histone H3 of P. falciparum is not found to complement Cse4p (the yeast homologue of CENH3). We also report the identification of PfCENP-C, another component of the inner kinetochore protein complex and its association with PfCENH3. These studies thus delineate the structural determinants of PfCENH3.
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Affiliation(s)
- Garima Verma
- Molecular Parasitology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Namita Surolia
- Molecular Parasitology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
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39
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Insights into chromatin structure and dynamics in plants. BIOLOGY 2013; 2:1378-410. [PMID: 24833230 PMCID: PMC4009787 DOI: 10.3390/biology2041378] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 11/15/2013] [Accepted: 11/18/2013] [Indexed: 11/17/2022]
Abstract
The packaging of chromatin into the nucleus of a eukaryotic cell requires an extraordinary degree of compaction and physical organization. In recent years, it has been shown that this organization is dynamically orchestrated to regulate responses to exogenous stimuli as well as to guide complex cell-type-specific developmental programs. Gene expression is regulated by the compartmentalization of functional domains within the nucleus, by distinct nucleosome compositions accomplished via differential modifications on the histone tails and through the replacement of core histones by histone variants. In this review, we focus on these aspects of chromatin organization and discuss novel approaches such as live cell imaging and photobleaching as important tools likely to give significant insights into our understanding of the very dynamic nature of chromatin and chromatin regulatory processes. We highlight the contribution plant studies have made in this area showing the potential advantages of plants as models in understanding this fundamental aspect of biology.
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40
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Kato H, Jiang J, Zhou BR, Rozendaal M, Feng H, Ghirlando R, Xiao TS, Straight AF, Bai Y. A conserved mechanism for centromeric nucleosome recognition by centromere protein CENP-C. Science 2013; 340:1110-3. [PMID: 23723239 PMCID: PMC3763809 DOI: 10.1126/science.1235532] [Citation(s) in RCA: 244] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Chromosome segregation during mitosis requires assembly of the kinetochore complex at the centromere. Kinetochore assembly depends on specific recognition of the histone variant CENP-A in the centromeric nucleosome by centromere protein C (CENP-C). We have defined the determinants of this recognition mechanism and discovered that CENP-C binds a hydrophobic region in the CENP-A tail and docks onto the acidic patch of histone H2A and H2B. We further found that the more broadly conserved CENP-C motif uses the same mechanism for CENP-A nucleosome recognition. Our findings reveal a conserved mechanism for protein recruitment to centromeres and a histone recognition mode whereby a disordered peptide binds the histone tail through hydrophobic interactions facilitated by nucleosome docking.
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Affiliation(s)
- Hidenori Kato
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Jiansheng Jiang
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Bing-Rui Zhou
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Marieke Rozendaal
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hanqiao Feng
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Rodolfo Ghirlando
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892
| | - T. Sam Xiao
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Aaron F. Straight
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yawen Bai
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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41
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Couesnon A, Offner N, Bernard V, Chaverot N, Backer S, Dimitrov A, Perez F, Molgó J, Bloch-Gallego E. CLIPR-59: a protein essential for neuromuscular junction stability during mouse late embryonic development. Development 2013; 140:1583-93. [PMID: 23482493 DOI: 10.1242/dev.087106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
CLIPR-59 is a new member of the cytoplasmic linker proteins (CLIP) family mainly localized to the trans-Golgi network. We show here that Clipr-59 expression in mice is restricted to specific pools of neurons, in particular motoneurons (MNs), and progressively increases from embryonic day 12.5 (E12.5) until the first postnatal days. We generated a Clipr-59 knockout mouse model that presents perinatal lethality due to respiratory defects. Physiological experiments revealed that this altered innervation prevents the normal nerve-elicited contraction of the mutant diaphragm that is reduced both in amplitude and fatigue-resistance at E18.5, despite unaffected functional muscular contractility. Innervation of the mutant diaphragm is not altered until E15.5, but is then partially lost in the most distal parts of the muscle. Ultrastructural observations of neuromuscular junctions (NMJs) in the distal region of the diaphragm reveal a normal organization, but a lower density of nerve terminals capped by terminal Schwann cells in E18.5 mutant when compared with control embryos. Similar defects in NMJ stability, with a hierarchy of severity along the caudo-rostral axis, are also observed in other muscles innervated by facial and spinal MNs in Clipr-59 mutant mice. Clipr-59 deficiency therefore affects axon maintenance but not axon guidance toward muscle targets. Thus, CLIPR-59 is involved in the stabilization of specific motor axons at the NMJ during mouse late embryogenesis and its role is crucial for mouse perinatal development.
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Affiliation(s)
- Aurélie Couesnon
- Institut Cochin, Université Paris Descartes, CNRS UMR 8104, Paris, France
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42
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Furuyama T, Codomo CA, Henikoff S. Reconstitution of hemisomes on budding yeast centromeric DNA. Nucleic Acids Res 2013; 41:5769-83. [PMID: 23620291 PMCID: PMC3675498 DOI: 10.1093/nar/gkt314] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The structure of nucleosomes that contain the cenH3 histone variant has been controversial. In budding yeast, a single right-handed cenH3/H4/H2A/H2B tetramer wraps the ∼80-bp Centromere DNA Element II (CDE II) sequence of each centromere into a ‘hemisome’. However, attempts to reconstitute cenH3 particles in vitro have yielded exclusively ‘octasomes’, which are observed in vivo on chromosome arms only when Cse4 (yeast cenH3) is overproduced. Here, we show that Cse4 octamers remain intact under conditions of low salt and urea that dissociate H3 octamers. However, particles consisting of two DNA duplexes wrapped around a Cse4 octamer and separated by a gap efficiently split into hemisomes. Hemisome dimensions were confirmed using a calibrated gel-shift assay and atomic force microscopy, and their identity as tightly wrapped particles was demonstrated by gelFRET. Surprisingly, Cse4 hemisomes were stable in 4 M urea. Stable Cse4 hemisomes could be reconstituted using either full-length or tailless histones and with a 78-bp CDEII segment, which is predicted to be exceptionally stiff. We propose that CDEII DNA stiffness evolved to favor Cse4 hemisome over octasome formation. The precise correspondence between Cse4 hemisomes resident on CDEII in vivo and reconstituted on CDEII in vitro without any other factors implies that CDEII is sufficient for hemisome assembly.
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Affiliation(s)
- Takehito Furuyama
- Howard Hughes Medical Institute and Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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43
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Tschernyschkow S, Herda S, Gruenert G, Döring V, Görlich D, Hofmeister A, Hoischen C, Dittrich P, Diekmann S, Ibrahim B. Rule-based modeling and simulations of the inner kinetochore structure. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2013; 113:33-45. [PMID: 23562479 DOI: 10.1016/j.pbiomolbio.2013.03.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Combinatorial complexity is a central problem when modeling biochemical reaction networks, since the association of a few components can give rise to a large variation of protein complexes. Available classical modeling approaches are often insufficient for the analysis of very large and complex networks in detail. Recently, we developed a new rule-based modeling approach that facilitates the analysis of spatial and combinatorially complex problems. Here, we explore for the first time how this approach can be applied to a specific biological system, the human kinetochore, which is a multi-protein complex involving over 100 proteins. RESULTS Applying our freely available SRSim software to a large data set on kinetochore proteins in human cells, we construct a spatial rule-based simulation model of the human inner kinetochore. The model generates an estimation of the probability distribution of the inner kinetochore 3D architecture and we show how to analyze this distribution using information theory. In our model, the formation of a bridge between CenpA and an H3 containing nucleosome only occurs efficiently for higher protein concentration realized during S-phase but may be not in G1. Above a certain nucleosome distance the protein bridge barely formed pointing towards the importance of chromatin structure for kinetochore complex formation. We define a metric for the distance between structures that allow us to identify structural clusters. Using this modeling technique, we explore different hypothetical chromatin layouts. CONCLUSIONS Applying a rule-based network analysis to the spatial kinetochore complex geometry allowed us to integrate experimental data on kinetochore proteins, suggesting a 3D model of the human inner kinetochore architecture that is governed by a combinatorial algebraic reaction network. This reaction network can serve as bridge between multiple scales of modeling. Our approach can be applied to other systems beyond kinetochores.
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Affiliation(s)
- Sergej Tschernyschkow
- Bio Systems Analysis Group, Institute of Computer Science, Jena Centre for Bioinformatics and Friedrich Schiller University, Jena, Germany.
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Shivaraju M, Unruh JR, Slaughter BD, Mattingly M, Berman J, Gerton JL. Cell-cycle-coupled structural oscillation of centromeric nucleosomes in yeast. Cell 2012; 150:304-16. [PMID: 22817893 DOI: 10.1016/j.cell.2012.05.034] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 03/16/2012] [Accepted: 05/18/2012] [Indexed: 11/17/2022]
Abstract
The centromere is a specialized chromosomal structure that regulates chromosome segregation. Centromeres are marked by a histone H3 variant. In budding yeast, the histone H3 variant Cse4 is present in a single centromeric nucleosome. Experimental evidence supports several different models for the structure of centromeric nucleosomes. To investigate Cse4 copy number in live yeast, we developed a method coupling fluorescence correlation spectroscopy and calibrated imaging. We find that centromeric nucleosomes have one copy of Cse4 during most of the cell cycle, whereas two copies are detected at anaphase. The proposal of an anaphase-coupled structural change is supported by Cse4-Cse4 interactions, incorporation of Cse4, and the absence of Scm3 in anaphase. Nucleosome reconstitution and ChIP suggests both Cse4 structures contain H2A/H2B. The increase in Cse4 intensity and deposition at anaphase are also observed in Candida albicans. Our experimental evidence supports a cell-cycle-coupled oscillation of centromeric nucleosome structure in yeast.
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Mills DR, Rozich RA, Flanagan DL, Brilliant KE, Yang D, Hixson DC. The cholangiocyte marker, BD. 1, forms a stable complex with CLIP170 and shares an identity with eIF3a, a multifunctional subunit of the eIF3 initiation complex. Exp Mol Pathol 2012; 93:250-60. [PMID: 22613460 DOI: 10.1016/j.yexmp.2012.04.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 04/15/2012] [Indexed: 11/26/2022]
Abstract
We have previously described the generation of a monoclonal antibody recognizing a novel cholangiocyte marker, designated BD.1, that is expressed by fetal and adult rat cholangiocytes but not hepatocytes or the hepatic progenitor cells known as oval cells. In the present report, we have undertaken a comprehensive examination of BD.1 expressed by long-term cultures of bile duct epithelial cells (BDEC) and prostate epithelial cells (PEC). We show that with continued passage, the levels of BD.1 expressed by BDEC and PEC drop significantly, a decrease that is temporally associated with transition from a diploid to an aneuploid karyotype. Cell cycle analysis revealed cell cycle dependent expression of BD.1 characterized by decreased BD.1 levels within the first 10 h after release from serum starvation followed by reacquisition as cells entered S phase. MAb BD.1 recognized a 170 kDa protein in Western blots and showed strong reactivity with a 170 kDa band in blots prepared from phosphoproteins isolated by metal affinity chromatography. Analysis by mass spectrometry of tryptic peptides generated from BD.1 purified by continuous elution electrophoresis identified the plus end microtubule-binding protein, CLIP170, in the fraction reactive with MAb BD.1. Double immunofluorescence with MAb BD.1 and a MAb specific for CLIP170 showed that both were reactive with intrahepatic bile ducts. However, overexpression or siRNA knockdown of CLIP170 in 293T cells did not significantly alter BD.1 levels, indicating that CLIP170 and BD.1 were distinct, co-migrating proteins. Immunoprecipitation analysis with MAb BD.1 and anti-CLIP170 antibodies showed that under microtubule depolymerizing conditions the two proteins could be co-precipitated with both antibodies, leading us to conclude they were capable of forming stable complexes. Two different protocols were devised to enrich for the CLIP170 binding protein recognized by MAb BD.1. Analysis of tryptic peptides by LC-ESI-MS/MS identified BD.1 as eIF3a, the largest subunit of the elongation initiation factor 3 (eIF3) complex. This identity was confirmed by the simultaneous knockdown of both BD.1 and eIF3a by eIF3a-specific siRNAs and by the strong reactivity of MAb BD.1 with the 170 kDa protein immunoprecipitated with the anti-eIF3a antibody, 5H10. Based on these findings, we concluded that the BD.1 antigen was identical to eIF3a, a multifunctional subunit of the eIf3 complex shown here to associate with microtubules through its interactions with CLIP170.
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Affiliation(s)
- David R Mills
- Department of Medicine, Division of Hematology and Oncology, Rhode Island Hospital/The Warren Alpert Medical School of Brown University, Providence, RI 02903, USA.
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The unconventional structure of centromeric nucleosomes. Chromosoma 2012; 121:341-52. [PMID: 22552438 PMCID: PMC3401303 DOI: 10.1007/s00412-012-0372-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 04/09/2012] [Accepted: 04/10/2012] [Indexed: 12/11/2022]
Abstract
The centromere is a defining feature of the eukaryotic chromosome, required for attachment to spindle microtubules and segregation to the poles at both mitosis and meiosis. The fundamental unit of centromere identity is the centromere-specific nucleosome, in which the centromeric histone 3 (cenH3) variant takes the place of H3. The structure of the cenH3 nucleosome has been the subject of controversy, as mutually exclusive models have been proposed, including conventional and unconventional left-handed octamers (octasomes), hexamers with non-histone protein constituents, and right-handed heterotypic tetramers (hemisomes). Hemisomes have been isolated from native centromeric chromatin, but traditional nucleosome assembly protocols have generally yielded partially unwrapped left-handed octameric nucleosomes. In budding yeast, topology analysis and high-resolution mapping has revealed that a single right-handed cenH3 hemisome occupies the ~80-bp Centromere DNA Element II (CDEII) of each chromosome. Overproduction of cenH3 leads to promiscuous low-level incorporation of octasome-sized particles throughout the yeast genome. We propose that the right-handed cenH3 hemisome is the universal unit of centromeric chromatin, and that the inherent instability of partially unwrapped left-handed cenH3 octamers is an adaptation to prevent formation of neocentromeres on chromosome arms.
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Choy JS, Mishra PK, Au WC, Basrai MA. Insights into assembly and regulation of centromeric chromatin in Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2012; 1819:776-83. [PMID: 22366340 DOI: 10.1016/j.bbagrm.2012.02.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 02/08/2012] [Accepted: 02/10/2012] [Indexed: 12/30/2022]
Abstract
At the core of chromosome segregation is the centromere, which nucleates the assembly of a macromolecular kinetochore (centromere DNA and associated proteins) complex responsible for mediating spindle attachment. Recent advances in centromere research have led to identification of many kinetochore components, such as the centromeric-specific histone H3 variant, CenH3, and its interacting partner, Scm3. Both are essential for chromosome segregation and are evolutionarily conserved from yeast to humans. CenH3 is proposed to be the epigenetic mark that specifies centromeric identity. Molecular mechanisms that regulate the assembly of kinetochores at specific chromosomal sites to mediate chromosome segregation are not fully understood. In this review, we summarize the current literature and discuss results from our laboratory, which show that restricting the localization of budding yeast CenH3, Cse4, to centromeres and balanced stoichiometry between Scm3 and Cse4, contribute to faithful chromosome transmission. We highlight our findings that, similar to other eukaryotic centromeres, budding yeast centromeric histone H4 is hypoacetylated, and we discuss how altered histone acetylation affects chromosome segregation. This article is part of a Special Issue entitled: Chromatin in time and space.
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Affiliation(s)
- John S Choy
- Genetics Branch Center for Cancer research, National Cancer Institute, National Institutes of Health, 41 Medlars Drive, Bethesda, MD 20892, USA
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Valdivia MM, Hamdouch K, Ortiz M, Astola A. CENPA a genomic marker for centromere activity and human diseases. Curr Genomics 2011; 10:326-35. [PMID: 20119530 PMCID: PMC2729997 DOI: 10.2174/138920209788920985] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Revised: 05/25/2009] [Accepted: 05/28/2009] [Indexed: 01/15/2023] Open
Abstract
Inheritance of genetic material requires that chromosomes segregate faithfully during cell division. Failure in this process can drive to aneuploidy phenomenon. Kinetochores are unique centromere macromolecular protein structures that attach chromosomes to the spindle for a proper movement and segregation. A unique type of nucleosomes of centromeric chromatin provides the base for kinetochore formation. A specific histone H3 variant, CENPA, replaces conventional histone H3 and together with centromere-specific-DNA-binding factors directs the assembly of active kinetochores. Recent studies on CENPA nucleosomal structure, epigenetic inheritance of centromeric chromatin and transcription of pericentric heterochromatin provide new clues to our understanding of centromere structure and function. This review highlights the role and dynamics of CENPA assembly into centromeres and the potential contribution of this kinetochore protein to autoimmune and cancer diseases in humans.
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Affiliation(s)
- Manuel M Valdivia
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain.
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Perpelescu M, Fukagawa T. The ABCs of CENPs. Chromosoma 2011; 120:425-46. [PMID: 21751032 DOI: 10.1007/s00412-011-0330-0] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 06/28/2011] [Accepted: 06/28/2011] [Indexed: 01/08/2023]
Abstract
Equal distribution of DNA in mitosis requires the assembly of a large proteinaceous ensemble onto the centromeric DNA, called the kinetochore. With few exceptions, kinetochore specification is independent of the DNA sequence and is determined epigenetically by deposition at the centromeric chromatin of special nucleosomes containing an H3-related histone, CENP-A. Onto centromeric CENP-A chromatin is assembled the so-called constitutive centromere-associated network (CCAN) of 16 proteins distributed in several functional groups as follows: CENP-C, CENP-H/CENP-I/CENP-K/, CENP-L/CENP-M/CENP-N, CENP-O/CENP-P/CENP-Q/CENP-R/CENP-U(50), CENP-T/CENP-W, and CENP-S/CENP-X. One role of the CCAN is to recruit outer kinetochore components further, such as KNL1, the Mis12 complex, and the Ndc80 complex (KMN network) to which attach the spindle microtubules with their structural and regulatory proteins. Among the CENPs in CCAN, CENP-C and CENP-T are required in parallel for operational kinetochore specification and spindle attachment. This review presents discussion of the latest structural and functional data on CENP-A and CENPs from the CCAN as well as their interaction with the KMN network.
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Affiliation(s)
- Marinela Perpelescu
- Department of Molecular Genetics, National Institute of Genetics and the Graduate University for Advanced Studies, Mishima, Shizuoka, Japan
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Ravi M, Shibata F, Ramahi JS, Nagaki K, Chen C, Murata M, Chan SWL. Meiosis-specific loading of the centromere-specific histone CENH3 in Arabidopsis thaliana. PLoS Genet 2011; 7:e1002121. [PMID: 21695238 PMCID: PMC3111537 DOI: 10.1371/journal.pgen.1002121] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Accepted: 04/21/2011] [Indexed: 01/12/2023] Open
Abstract
Centromere behavior is specialized in meiosis I, so that sister chromatids of homologous chromosomes are pulled toward the same side of the spindle (through kinetochore mono-orientation) and chromosome number is reduced. Factors required for mono-orientation have been identified in yeast. However, comparatively little is known about how meiotic centromere behavior is specialized in animals and plants that typically have large tandem repeat centromeres. Kinetochores are nucleated by the centromere-specific histone CENH3. Unlike conventional histone H3s, CENH3 is rapidly evolving, particularly in its N-terminal tail domain. Here we describe chimeric variants of CENH3 with alterations in the N-terminal tail that are specifically defective in meiosis. Arabidopsis thaliana cenh3 mutants expressing a GFP-tagged chimeric protein containing the H3 N-terminal tail and the CENH3 C-terminus (termed GFP-tailswap) are sterile because of random meiotic chromosome segregation. These defects result from the specific depletion of GFP-tailswap protein from meiotic kinetochores, which contrasts with its normal localization in mitotic cells. Loss of the GFP-tailswap CENH3 variant in meiosis affects recruitment of the essential kinetochore protein MIS12. Our findings suggest that CENH3 loading dynamics might be regulated differently in mitosis and meiosis. As further support for our hypothesis, we show that GFP-tailswap protein is recruited back to centromeres in a subset of pollen grains in GFP-tailswap once they resume haploid mitosis. Meiotic recruitment of the GFP-tailswap CENH3 variant is not restored by removal of the meiosis-specific cohesin subunit REC8. Our results reveal the existence of a specialized loading pathway for CENH3 during meiosis that is likely to involve the hypervariable N-terminal tail. Meiosis-specific CENH3 dynamics may play a role in modulating meiotic centromere behavior. There are two types of cell division in eukaryotes. Mitosis produces cells with identical copies of the genome, while meiosis produces gametes with half the number of chromosomes found in the parent cell. Faithful genome inheritance is controlled by centromeres, chromosomal structures that allow duplicated chromosomes to be pulled apart correctly during cell division. Centromeres are differentially configured during meiosis (relative to mitosis) so chromosome number can be reduced by half. Centromeres are built upon a specialized DNA packing protein, CENH3. Here we describe altered forms of CENH3 that are loaded correctly during mitosis but are severely depleted from centromeres in meiotic cells. As CENH3 is essential for chromosome inheritance, plants expressing these versions of the protein are sterile because they produce very few viable gametes. Differential loading of CENH3 during meiosis may play a role in modulating chromosome inheritance to form haploid gametes.
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Affiliation(s)
- Maruthachalam Ravi
- Department of Plant Biology, University of California Davis, Davis, California, United States of America
| | - Fukashi Shibata
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Joseph S. Ramahi
- Department of Plant Biology, University of California Davis, Davis, California, United States of America
| | - Kiyotaka Nagaki
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Changbin Chen
- Department of Horticultural Science, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Minoru Murata
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Japan
| | - Simon W. L. Chan
- Department of Plant Biology, University of California Davis, Davis, California, United States of America
- * E-mail:
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