scholarly journals Getting there: understanding the chromosomal recruitment of the AAA+ ATPase Pch2/TRIP13 during meiosis

2021 ◽  
Author(s):  
Richard Cardoso da Silva ◽  
Gerben Vader
Keyword(s):  
Rna Polymerase Ii ◽  
Meiotic Recombination ◽  
Origin Recognition Complex ◽  
Comprehensive Overview ◽  
Homologous Chromosomes ◽  
Functional Roles ◽  
Aaa Atpase ◽  
Meiotic Chromosomes ◽  
Chromosomal Association ◽  
Dna Break

AbstractThe generally conserved AAA+ ATPase Pch2/TRIP13 is involved in diverse aspects of meiosis, such as prophase checkpoint function, DNA break regulation, and meiotic recombination. The controlled recruitment of Pch2 to meiotic chromosomes allows it to use its ATPase activity to influence HORMA protein-dependent signaling. Because of the connection between Pch2 chromosomal recruitment and its functional roles in meiosis, it is important to reveal the molecular details that govern Pch2 localization. Here, we review the current understanding of the different factors that control the recruitment of Pch2 to meiotic chromosomes, with a focus on research performed in budding yeast. During meiosis in this organism, Pch2 is enriched within the nucleolus, where it likely associates with the specialized chromatin of the ribosomal (r)DNA. Pch2 is also found on non-rDNA euchromatin, where its recruitment is contingent on Zip1, a component of the synaptonemal complex (SC) that assembles between homologous chromosomes. We discuss recent findings connecting the recruitment of Pch2 with its association with the Origin Recognition Complex (ORC) and reliance on RNA Polymerase II-dependent transcription. In total, we provide a comprehensive overview of the pathways that control the chromosomal association of an important meiotic regulator.

scholarly journals Active transcription and Orc1 drive chromatin association of the AAA+ ATPase Pch2 during meiotic G2/prophase

2019 ◽  
Author(s):  
Richard Cardoso da Silva ◽  
María Ascensión Villar-Fernández ◽  
Gerben Vader
Keyword(s):  
Rna Polymerase Ii ◽  
Origin Recognition Complex ◽  
Budding Yeast ◽  
Yeast Genome ◽  
Checkpoint Signaling ◽  
Aaa Atpase ◽  
Meiotic Chromosomes ◽  
Chromosomal Association ◽  
Active Transcription ◽  
And Function

AbstractPch2 is an AAA+ protein that controls DNA break formation, recombination and checkpoint signaling during meiotic G2/prophase. Chromosomal association of Pch2 is linked to these processes, and several factors influence the association of Pch2 to euchromatin and the specialized chromatin of the ribosomal (r)DNA array of budding yeast. Here, we describe a comprehensive mapping of Pch2 localization across the budding yeast genome during meiotic G2/prophase. Within non-rDNA chromatin, Pch2 associates with a subset of actively RNA Polymerase II (RNAPII)-dependent transcribed genes. Chromatin immunoprecipitation (ChIP)- and microscopy-based analysis reveals that active transcription is required for chromosomal recruitment of Pch2. Similar to what was previously established for association of Pch2 with rDNA chromatin, we find that Orc1, a component of the Origin Recognition Complex (ORC), is required for the association of Pch2 to these euchromatic, transcribed regions, revealing a broad connection between chromosomal association of Pch2 and Orc1/ORC function. Ectopic mitotic expression is insufficient to drive recruitment of Pch2, despite the presence of active transcription and Orc1/ORC in mitotic cells. This suggests meiosis-specific ‘licensing’ of Pch2 recruitment to sites of transcription, and accordingly, we find that the synaptonemal complex (SC) component Zip1 is required for the recruitment of Pch2 to transcription-associated binding regions. Interestingly, Pch2 binding patterns are distinct from meiotic axis enrichment sites (as defined by Red1, Hop1 and Rec8). This suggests that although Pch2 is linked to axis/SC-directed recruitment and function, the chromosomal population of Pch2 described here is not directly associated with chromosomal axis sites. In line with this observation, interfering with the pool of Pch2 that associates with active RNAPII transcription does not lead to effects on the chromosomal abundance of Hop1, a known axial client of Pch2. We thus report characteristics and dependencies for Pch2 recruitment to meiotic chromosomes, and reveal an unexpected link between Pch2, SC formation, chromatin and active transcription.

scholarly journals The synaptonemal complex has liquid crystalline properties and spatially regulates meiotic recombination factors

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Ofer Rog ◽  
Simone Köhler ◽  
Abby F Dernburg
Keyword(s):  
Signal Transduction ◽  
Synaptonemal Complex ◽  
Meiotic Recombination ◽  
Liquid Crystalline ◽  
Hydrophobic Interactions ◽  
Rapid Evolution ◽  
Three Dimensional ◽  
Homologous Chromosomes ◽  
Meiotic Progression ◽  
Meiotic Chromosomes

The synaptonemal complex (SC) is a polymer that spans ~100 nm between paired homologous chromosomes during meiosis. Its striated, periodic appearance in electron micrographs led to the idea that transverse filaments within this structure ‘crosslink’ the axes of homologous chromosomes, stabilizing their pairing. SC proteins can also form polycomplexes, three-dimensional lattices that recapitulate the periodic structure of SCs but do not associate with chromosomes. Here we provide evidence that SCs and polycomplexes contain mobile subunits and that their assembly is promoted by weak hydrophobic interactions, indicative of a liquid crystalline phase. We further show that in the absence of recombination intermediates, polycomplexes recapitulate the dynamic localization of pro-crossover factors during meiotic progression, revealing how the SC might act as a conduit to regulate chromosome-wide crossover distribution. Properties unique to liquid crystals likely enable long-range signal transduction along meiotic chromosomes and underlie the rapid evolution of SC proteins.

scholarly journals Mammalian BLM helicase is critical for integrating multiple pathways of meiotic recombination

2010 ◽  
Vol 188 (6) ◽  
pp. 779-789 ◽  
Author(s):  
J. Kim Holloway ◽  
Meisha A. Morelli ◽  
Peter L. Borst ◽  
Paula E. Cohen
Keyword(s):  
Meiotic Recombination ◽  
Genome Stability ◽  
Autosomal Recessive Disorder ◽  
Dna Structures ◽  
Homologous Chromosomes ◽  
Recq Helicases ◽  
Meiotic Progression ◽  
Meiotic Chromosomes ◽  
Conditional Mutant ◽  
Blm Helicase

Bloom’s syndrome (BS) is an autosomal recessive disorder characterized by growth retardation, cancer predisposition, and sterility. BS mutated (Blm), the gene mutated in BS patients, is one of five mammalian RecQ helicases. Although BLM has been shown to promote genome stability by assisting in the repair of DNA structures that arise during homologous recombination in somatic cells, less is known about its role in meiotic recombination primarily because of the embryonic lethality associated with Blm deletion. However, the localization of BLM protein on meiotic chromosomes together with evidence from yeast and other organisms implicates a role for BLM helicase in meiotic recombination events, prompting us to explore the meiotic phenotype of mice bearing a conditional mutant allele of Blm. In this study, we show that BLM deficiency does not affect entry into prophase I but causes severe defects in meiotic progression. This is exemplified by improper pairing and synapsis of homologous chromosomes and altered processing of recombination intermediates, resulting in increased chiasmata. Our data provide the first analysis of BLM function in mammalian meiosis and strongly argue that BLM is involved in proper pairing, synapsis, and segregation of homologous chromosomes; however, it is dispensable for the accumulation of recombination intermediates.

scholarly journals Mouse TEX15 is essential for DNA double-strand break repair and chromosomal synapsis during male meiosis

2008 ◽  
Vol 180 (4) ◽  
pp. 673-679 ◽  
Author(s):  
Fang Yang ◽  
Sigrid Eckardt ◽  
N. Adrian Leu ◽  
K. John McLaughlin ◽  
Peijing Jeremy Wang
Keyword(s):  
Meiotic Recombination ◽  
Strand Break ◽  
Male Meiosis ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Strand Breaks ◽  
Homologous Chromosomes ◽  
Recombination Proteins ◽  
Meiotic Chromosomes ◽  
Dna Double Strand Break

During meiosis, homologous chromosomes undergo synapsis and recombination. We identify TEX15 as a novel protein that is required for chromosomal synapsis and meiotic recombination. Loss of TEX15 function in mice causes early meiotic arrest in males but not in females. Specifically, TEX15-deficient spermatocytes exhibit a failure in chromosomal synapsis. In mutant spermatocytes, DNA double-strand breaks (DSBs) are formed, but localization of the recombination proteins RAD51 and DMC1 to meiotic chromosomes is severely impaired. Based on these data, we propose that TEX15 regulates the loading of DNA repair proteins onto sites of DSBs and, thus, its absence causes a failure in meiotic recombination.

scholarly journals Sharing Marks: H3K4 Methylation and H2B Ubiquitination as Features of Meiotic Recombination and Transcription

2020 ◽  
Vol 21 (12) ◽  
pp. 4510
Author(s):  
Joan Serrano-Quílez ◽  
Sergi Roig-Soucase ◽  
Susana Rodríguez-Navarro
Keyword(s):  
Rna Polymerase Ii ◽  
Posttranslational Modifications ◽  
Meiotic Recombination ◽  
Driving Forces ◽  
Diploid Cell ◽  
Dna Double Strand Breaks ◽  
Histone Tails ◽  
Strand Breaks ◽  
Homologous Chromosomes ◽  
Molecular Events

Meiosis is a specialized cell division that gives raise to four haploid gametes from a single diploid cell. During meiosis, homologous recombination is crucial to ensure genetic diversity and guarantee accurate chromosome segregation. Both the formation of programmed meiotic DNA double-strand breaks (DSBs) and their repair using homologous chromosomes are essential and highly regulated pathways. Similar to other processes that take place in the context of chromatin, histone posttranslational modifications (PTMs) constitute one of the major mechanisms to regulate meiotic recombination. In this review, we focus on specific PTMs occurring in histone tails as driving forces of different molecular events, including meiotic recombination and transcription. In particular, we concentrate on the influence of H3K4me3, H2BK123ub, and their corresponding molecular machineries that write, read, and erase these histone marks. The Spp1 subunit within the Complex of Proteins Associated with Set1 (COMPASS) is a critical regulator of H3K4me3-dependent meiotic DSB formation. On the other hand, the PAF1c (RNA polymerase II associated factor 1 complex) drives the ubiquitination of H2BK123 by Rad6-Bre1. We also discuss emerging evidence obtained by cryo-electron microscopy (EM) structure determination that has provided new insights into how the “cross-talk” between these two marks is accomplished.

scholarly journals SCFCdc4 ubiquitin ligase regulates synaptonemal complex formation during meiosis

2020 ◽  
Author(s):  
Zhihui Zhu ◽  
Mohammad Bani Ismail ◽  
Miki Shinohara ◽  
Akira Shinohara
Keyword(s):  
Synaptonemal Complex ◽  
Ubiquitin Ligase ◽  
Meiotic Recombination ◽  
Critical Role ◽  
Temperature Sensitive ◽  
Gene Encoding ◽  
Homologous Chromosomes ◽  
Aaa Atpase ◽  
F Box Protein ◽  
Cycle Regulation

AbstractHomologous chromosomes pair with each other during meiosis, culminating in the formation of the synaptonemal complex (SC), which is coupled with meiotic recombination. In this study, we showed that a meiosis-specific depletion mutant of a cullin (Cdc53) of the SCF (Skp-Cullin-F-box) ubiquitin ligase, which plays a critical role in cell cycle regulation during mitosis, is deficient in SC formation, but is proficient in the formation of crossovers, indicating uncoupling of meiotic recombination with SC formation in the mutant. Furthermore, the deletion of the PCH2 gene encoding a meiosis-specific AAA+ ATPase suppresses SC-assembly defect induced by CDC53 depletion. On the other hand, the pch2 cdc53 double mutant is defective in meiotic crossover formation, suggesting the SC assembly with unrepaired DSBs. A temperature-sensitive mutant of the CDC4, which encodes a F-box protein of the SCF, shows similar meiotic defects to the CDC53 depletion mutant. These suggest that SCFCdc4, probably SCFCdc4-dependnet protein ubiquitylation, regulates and collaborates with Pch2 in SC assembly and meiotic recombination.SummaryDuring meiosis, homologous chromosomes pair with each other and form the synaptonemal complex (SC). In this study, components of the SCF (Skp-Cullin-F-box) ubiquitin ligase, Cdc53 and Cdc4, are required for SC formation. A meiosis-specific AAA+ ATPase Pch2 antagonize the functions of Cdc53 and Cdc4 for proper SC assembly.

scholarly journals Molecular organization of mammalian meiotic chromosome axis revealed by expansion STORM microscopy

2019 ◽  
Vol 116 (37) ◽  
pp. 18423-18428 ◽  
Author(s):  
Huizhong Xu ◽  
Zhisong Tong ◽  
Qing Ye ◽  
Tengqian Sun ◽  
Zhenmin Hong ◽  
...  
Keyword(s):  
Meiotic Chromosome ◽  
Molecular Organization ◽  
Homologous Chromosomes ◽  
Meiotic Chromosomes ◽  
C Terminus ◽  
Stochastic Optical Reconstruction Microscopy ◽  
Optical Reconstruction ◽  
20 Nm ◽  
Chromosome Axis

During prophase I of meiosis, chromosomes become organized as loop arrays around the proteinaceous chromosome axis. As homologous chromosomes physically pair and recombine, the chromosome axis is integrated into the tripartite synaptonemal complex (SC) as this structure’s lateral elements (LEs). While the components of the mammalian chromosome axis/LE—including meiosis-specific cohesin complexes, the axial element proteins SYCP3 and SYCP2, and the HORMA domain proteins HORMAD1 and HORMAD2—are known, the molecular organization of these components within the axis is poorly understood. Here, using expansion microscopy coupled with 2-color stochastic optical reconstruction microscopy (STORM) imaging (ExSTORM), we address these issues in mouse spermatocytes at a resolution of 10 to 20 nm. Our data show that SYCP3 and the SYCP2 C terminus, which are known to form filaments in vitro, form a compact core around which cohesin complexes, HORMADs, and the N terminus of SYCP2 are arrayed. Overall, our study provides a detailed structural view of the meiotic chromosome axis, a key organizational and regulatory component of meiotic chromosomes.

scholarly journals A human cancer cell line initiates DNA replication normally in the absence of ORC5 and ORC2 proteins

2020 ◽  
Vol 295 (50) ◽  
pp. 16949-16959
Author(s):  
Etsuko Shibata ◽  
Anindya Dutta
Keyword(s):  
Dna Replication ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Origin Recognition Complex ◽  
Human Cancer ◽  
Cancer Cell Line ◽  
Aaa Atpase ◽  
Normal Number ◽  
Mutant Cells

The origin recognition complex (ORC), composed of six subunits, ORC1–6, binds to origins of replication as a ring-shaped heterohexameric ATPase that is believed to be essential to recruit and load MCM2–7, the minichromosome maintenance protein complex, around DNA and initiate DNA replication. We previously reported the creation of viable cancer cell lines that lacked detectable ORC1 or ORC2 protein without a reduction in the number of origins firing. Here, using CRISPR-Cas9–mediated mutations, we report that human HCT116 colon cancer cells also survive when ORC5 protein expression is abolished via a mutation in the initiator ATG of the ORC5 gene. Even if an internal methionine is used to produce an undetectable, N terminally deleted ORC5, the protein would lack 80% of the AAA+ ATPase domain, including the Walker A motif. The ORC5-depleted cells show normal chromatin binding of MCM2–7 and initiate replication from a similar number of origins as WT cells. In addition, we introduced a second mutation in ORC2 in the ORC5 mutant cells, rendering both ORC5 and ORC2 proteins undetectable in the same cells and destabilizing the ORC1, ORC3, and ORC4 proteins. Yet the double mutant cells grow, recruit MCM2–7 normally to chromatin, and initiate DNA replication with normal number of origins. Thus, in these selected cancer cells, either a crippled ORC lacking ORC2 and ORC5 and present at minimal levels on the chromatin can recruit and load enough MCM2–7 to initiate DNA replication, or human cell lines can sometimes recruit MCM2–7 to origins independent of ORC.

scholarly journals A molecular model for the role of SYCP3 in meiotic chromosome organisation

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Johanna Liinamaria Syrjänen ◽  
Luca Pellegrini ◽  
Owen Richard Davies
Keyword(s):  
Molecular Model ◽  
Meiotic Chromosome ◽  
Lateral Element ◽  
Homologous Chromosomes ◽  
Meiotic Chromosomes ◽  
Double Stranded Dna ◽  
Evolutionarily Conserved ◽  
20 Nm ◽  
Chromosome Organisation

The synaptonemal complex (SC) is an evolutionarily-conserved protein assembly that holds together homologous chromosomes during prophase of the first meiotic division. Whilst essential for meiosis and fertility, the molecular structure of the SC has proved resistant to elucidation. The SC protein SYCP3 has a crucial but poorly understood role in establishing the architecture of the meiotic chromosome. Here we show that human SYCP3 forms a highly-elongated helical tetramer of 20 nm length. N-terminal sequences extending from each end of the rod-like structure bind double-stranded DNA, enabling SYCP3 to link distant sites along the sister chromatid. We further find that SYCP3 self-assembles into regular filamentous structures that resemble the known morphology of the SC lateral element. Together, our data form the basis for a model in which SYCP3 binding and assembly on meiotic chromosomes leads to their organisation into compact structures compatible with recombination and crossover formation.

scholarly journals One-dimensional spatial patterning along mitotic chromosomes: A mechanical basis for macroscopic morphogenesis

2020 ◽  
Vol 117 (43) ◽  
pp. 26749-26755
Author(s):  
Lingluo Chu ◽  
Zhangyi Liang ◽  
Maria V. Mukhina ◽  
Jay K. Fisher ◽  
John W. Hutchinson ◽  
...  
Keyword(s):  
Spatial Patterning ◽  
Geometric Form ◽  
Mitotic Chromosomes ◽  
Homologous Chromosomes ◽  
One Dimensional ◽  
Meiotic Chromosomes ◽  
Planar Arrays ◽  
Mechanical Basis ◽  
Continuous Presence ◽  
Morphological Patterns

Spatial patterns are ubiquitous in both physical and biological systems. We have recently discovered that mitotic chromosomes sequentially acquire two interesting morphological patterns along their structural axes [L. Chu et al., Mol. Cell, 10.1016/j.molcel.2020.07.002 (2020)]. First, axes of closely conjoined sister chromosomes acquire regular undulations comprising nearly planar arrays of sequential half-helices of similar size and alternating handedness, accompanied by periodic kinks. This pattern, which persists through all later stages, provides a case of the geometric form known as a “perversion.” Next, as sister chromosomes become distinct parallel units, their individual axes become linked by bridges, which are themselves miniature axes. These bridges are dramatically evenly spaced. Together, these effects comprise a unique instance of spatial patterning in a subcellular biological system. We present evidence that axis undulations and bridge arrays arise by a single continuous mechanically promoted progression, driven by stress within the chromosome axes. We further suggest that, after sister individualization, this same stress also promotes chromosome compaction by rendering the axes susceptible to the requisite molecular remodeling. Thus, by this scenario, the continuous presence of mechanical stress within the chromosome axes could potentially underlie the entire morphogenetic chromosomal program. Direct analogies with meiotic chromosomes suggest that the same effects could underlie interactions between homologous chromosomes as required for gametogenesis. Possible mechanical bases for generation of axis stress and resultant deformations are discussed. Together, these findings provide a perspective on the macroscopic changes of organized chromosomes.

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