Mec1/Tel1-independent role of protein phosphatase 4 in Hop1 assembly to promote meiotic chromosome axis formation in budding yeast

Mapping Intimacies ◽

10.1101/2021.05.10.443451 ◽

2021 ◽

Author(s):

Miki Shinohara

Keyword(s):

Protein Phosphatase ◽

Budding Yeast ◽

Meiotic Chromosome ◽

Integrated Control ◽

Initial Step ◽

Axis Formation ◽

Recombination Reaction ◽

Chromosomal Structure ◽

Aaa Atpase ◽

Chromosome Axis

Dynamic changes in chromosomal structure that occur during meiotic prophase play an important role in the progression of meiosis. Among them, meiosis-specific chromosomal axis-loop structures are important as a scaffold for integrated control between the meiotic recombination reaction and the associated checkpoint system to ensure accurate chromosome segregation. However, the molecular mechanism of the initial step of chromosome axis-loop construction is not well understood. Here, we showed that, in budding yeast, a Tel1/Mec1-related protein phosphatase 4 (PP4) is required to promote the assembly of a chromosomal axis components Hop1 and Red1 onto meiotic chromatin via interaction with Hop1. PP4 did not affect Rec8 assembly. Notably, unlike the previously known function of PP4, this novel function was independent of Tel1/Mec1 kinase functions. The defect in Hop1/Red1 assembly in the absence of PP4 function was not suppressed by Pch2 dysfunction. Since Pch2 is a conserved AAA+ ATPase and facilitates eviction of Hop1 protein from the chromosome axis, suggesting that PP4 is required for the initial step of chromatin loading of Hop1 rather than stabilizing Hop1 on the chromosome axis. These results indicate phosphorylation/dephosphorylation-mediated regulation of Hop1 recruitment onto chromatin during chromosome axis construction before meiotic double-strand break formation.

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A conserved filamentous assembly underlies the structure of the meiotic chromosome axis

eLife ◽

10.7554/elife.40372 ◽

2019 ◽

Vol 8 ◽

Cited By ~ 26

Author(s):

Alan MV West ◽

Scott C Rosenberg ◽

Sarah N Ur ◽

Madison K Lehmer ◽

Qiaozhen Ye ◽

...

Keyword(s):

Meiotic Recombination ◽

Budding Yeast ◽

Meiotic Chromosome ◽

Coiled Coil ◽

Chromosome Organization ◽

Molecular Architecture ◽

Master Regulators ◽

Core Proteins ◽

Protein Components ◽

Chromosome Axis

The meiotic chromosome axis plays key roles in meiotic chromosome organization and recombination, yet the underlying protein components of this structure are highly diverged. Here, we show that ‘axis core proteins’ from budding yeast (Red1), mammals (SYCP2/SYCP3), and plants (ASY3/ASY4) are evolutionarily related and play equivalent roles in chromosome axis assembly. We first identify ‘closure motifs’ in each complex that recruit meiotic HORMADs, the master regulators of meiotic recombination. We next find that axis core proteins form homotetrameric (Red1) or heterotetrameric (SYCP2:SYCP3 and ASY3:ASY4) coiled-coil assemblies that further oligomerize into micron-length filaments. Thus, the meiotic chromosome axis core in fungi, mammals, and plants shares a common molecular architecture, and likely also plays conserved roles in meiotic chromosome axis assembly and recombination control.

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Differential requirement for Bub1 and Bub3 in regulation of meiotic versus mitotic chromosome segregation

The Journal of Cell Biology ◽

10.1083/jcb.201909136 ◽

2020 ◽

Vol 219 (4) ◽

Cited By ~ 2

Author(s):

Gisela Cairo ◽

Anne M. MacKenzie ◽

Soni Lacefield

Keyword(s):

Chromosome Segregation ◽

Protein Phosphatase ◽

Mitotic Chromosome ◽

Budding Yeast ◽

Meiotic Chromosome ◽

Protein Phosphatase 1 ◽

Aurora B ◽

Chromosome Missegregation ◽

Anaphase Onset ◽

Spindle Microtubules

Accurate chromosome segregation depends on the proper attachment of kinetochores to spindle microtubules before anaphase onset. The Ipl1/Aurora B kinase corrects improper attachments by phosphorylating kinetochore components and so releasing aberrant kinetochore–microtubule interactions. The localization of Ipl1 to kinetochores in budding yeast depends upon multiple pathways, including the Bub1–Bub3 pathway. We show here that in meiosis, Bub3 is crucial for correction of attachment errors. Depletion of Bub3 results in reduced levels of kinetochore-localized Ipl1 and concomitant massive chromosome missegregation caused by incorrect chromosome–spindle attachments. Depletion of Bub3 also results in shorter metaphase I and metaphase II due to premature localization of protein phosphatase 1 (PP1) to kinetochores, which antagonizes Ipl1-mediated phosphorylation. We propose a new role for the Bub1–Bub3 pathway in maintaining the balance between kinetochore localization of Ipl1 and PP1, a balance that is essential for accurate meiotic chromosome segregation and timely anaphase onset.

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The Multiple Roles of Cohesin in Meiotic Chromosome Morphogenesis and Pairing

Molecular Biology of the Cell ◽

10.1091/mbc.e08-06-0637 ◽

2009 ◽

Vol 20 (3) ◽

pp. 1030-1047 ◽

Cited By ~ 61

Author(s):

Gloria A. Brar ◽

Andreas Hochwagen ◽

Ly-sha S. Ee ◽

Angelika Amon

Keyword(s):

Sister Chromatid ◽

Meiotic Prophase ◽

Meiotic Chromosome ◽

Sister Chromatid Cohesion ◽

Multiple Roles ◽

Axis Formation ◽

Chromatid Cohesion ◽

Cohesin Subunit ◽

Chromosome Axis ◽

Segregation Of Chromosomes

Sister chromatid cohesion, mediated by cohesin complexes, is laid down during DNA replication and is essential for the accurate segregation of chromosomes. Previous studies indicated that, in addition to their cohesion function, cohesins are essential for completion of recombination, pairing, meiotic chromosome axis formation, and assembly of the synaptonemal complex (SC). Using mutants in the cohesin subunit Rec8, in which phosphorylated residues were mutated to alanines, we show that cohesin phosphorylation is not only important for cohesin removal, but that cohesin's meiotic prophase functions are distinct from each other. We find pairing and SC formation to be dependent on Rec8, but independent of the presence of a sister chromatid and hence sister chromatid cohesion. We identified mutations in REC8 that differentially affect Rec8's cohesion, pairing, recombination, chromosome axis and SC assembly function. These findings define Rec8 as a key determinant of meiotic chromosome morphogenesis and a central player in multiple meiotic events.

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Transcription dynamically patterns the meiotic chromosome-axis interface

eLife ◽

10.7554/elife.07424 ◽

2015 ◽

Vol 4 ◽

Cited By ~ 49

Author(s):

Xiaoji Sun ◽

Lingzhi Huang ◽

Tovah E Markowitz ◽

Hannah G Blitzblau ◽

Doris Chen ◽

...

Keyword(s):

Protein Binding ◽

Budding Yeast ◽

Meiotic Chromosome ◽

Cohesin Complex ◽

Protein Enrichment ◽

Meiotic Chromosomes ◽

Convergent Transcription ◽

Chromosome Axis ◽

Ubiquitous Presence ◽

Axial Element

Meiotic chromosomes are highly compacted yet remain transcriptionally active. To understand how chromosome folding accommodates transcription, we investigated the assembly of the axial element, the proteinaceous structure that compacts meiotic chromosomes and promotes recombination and fertility. We found that the axial element proteins of budding yeast are flexibly anchored to chromatin by the ring-like cohesin complex. The ubiquitous presence of cohesin at sites of convergent transcription provides well-dispersed points for axis attachment and thus chromosome compaction. Axis protein enrichment at these sites directly correlates with the propensity for recombination initiation nearby. A separate modulating mechanism that requires the conserved axial-element component Hop1 biases axis protein binding towards small chromosomes. Importantly, axis anchoring by cohesin is adjustable and readily displaced in the direction of transcription by the transcriptional machinery. We propose that such robust but flexible tethering allows the axial element to promote recombination while easily adapting to changes in chromosome activity.

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Meiotic chromosome axis remodelling is critical for meiotic recombination in Brassica rapa

Journal of Experimental Botany ◽

10.1093/jxb/erab035 ◽

2021 ◽

Author(s):

Maria Cuacos ◽

Christophe Lambing ◽

Miguel Pachon-Penalba ◽

Kim Osman ◽

Susan J Armstrong ◽

...

Keyword(s):

Brassica Rapa ◽

Meiotic Chromosome ◽

Axis Formation ◽

Crop Species ◽

Breeding Programs ◽

Distal Chromosome ◽

Chromosome Arm ◽

Chromosome Axis ◽

Chromosome Regions

Abstract Meiosis generates genetic variation through homologous recombination (HR) that is harnessed during breeding. HR occurs in the context of meiotic chromosome axes and the synaptonemal complex. To study the role of axis remodelling on crossover (CO) formation in a crop species, we characterized mutants of the axis-associated protein ASY1 and the axis-remodelling protein PCH2 in Brassica rapa. asy1 plants form meiotic chromosome axes that fail to synapse. CO formation is almost abolished and residual chiasmata are proportionally enriched in terminal chromosome regions, particularly in the nucleolar organizing region (NOR)-carrying chromosome arm. pch2 plants show impaired ASY1 loading and remodelling consequently achieving only partial synapsis, which leads to reduced CO formation and loss of the obligatory CO. PCH2-independent chiasmata are proportionally enriched towards distal chromosome regions. Similarly, in Arabidopsis pch2 COs are increased towards telomeric regions at the expense of (peri-)centromeric COs compared to WT. Together, in B. rapa axis formation and remodelling are critical for meiotic fidelity including synapsis and CO formation and in asy1 and pch2 CO distributions are altered. While asy1 plants are sterile, pch2 plants are semi-sterile and thus PCH2 could be an interesting target for breeding programs.

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Local chromosome context is a major determinant of crossover pathway biochemistry during budding yeast meiosis

10.1101/064519 ◽

2016 ◽

Author(s):

Darpan Medhi ◽

Alastair S. H. Goldman ◽

Michael Lichten

Keyword(s):

Meiotic Recombination ◽

Chromosome Structure ◽

Budding Yeast ◽

Meiotic Chromosome ◽

Major Determinant ◽

The Other ◽

Biochemical Mechanism ◽

Meiotic Chromosomes ◽

Yeast Meiosis ◽

Chromosome Axis

AbstractMeiotic chromosomes are divided into regions of enrichment and depletion for meiotic chromosome axis proteins, in budding yeast Hop1 and Red1. These proteins are important for formation of Spo11-catalyzed DSB, but their contribution to crossover recombination is undefined. By studying meiotic recombination initiated by the sequence-specificVMA1-derived endonuclease (VDE), we show that meiotic chromosome structure helps to determine the biochemical mechanism by which recombination intermediates are resolved to form crossovers. At a Hop1-enriched locus, most VDE-initiated crossovers required the MutLγ resolvase, which forms most Spo11-initiated crossovers. In contrast, at a locus with lower Hop1 occupancy, most VDE-initiated crossovers were MutLγ-independent. Inpch2mutants, the two loci displayed similar Hop1 occupancy levels, and also displayed similar MutLγ-dependence of VDE-induced crossovers. We suggest that meiotic and mitotic recombination pathways coexist within meiotic cells, with features of meiotic chromosome structure partitioning the genome into regions where one pathway or the other predominates.

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Local chromosome context is a major determinant of crossover pathway biochemistry during budding yeast meiosis

eLife ◽

10.7554/elife.19669 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 17

Author(s):

Darpan Medhi ◽

Alastair SH Goldman ◽

Michael Lichten

Keyword(s):

Meiotic Recombination ◽

Chromosome Structure ◽

Budding Yeast ◽

Meiotic Chromosome ◽

Strand Break ◽

The Other ◽

Yeast Genome ◽

Yeast Meiosis ◽

Chromosome Axis ◽

Break Formation

The budding yeast genome contains regions where meiotic recombination initiates more frequently than in others. This pattern parallels enrichment for the meiotic chromosome axis proteins Hop1 and Red1. These proteins are important for Spo11-catalyzed double strand break formation; their contribution to crossover recombination remains undefined. Using the sequence-specific VMA1-derived endonuclease (VDE) to initiate recombination in meiosis, we show that chromosome structure influences the choice of proteins that resolve recombination intermediates to form crossovers. At a Hop1-enriched locus, most VDE-initiated crossovers, like most Spo11-initiated crossovers, required the meiosis-specific MutLγ resolvase. In contrast, at a locus with lower Hop1 occupancy, most VDE-initiated crossovers were MutLγ-independent. In pch2 mutants, the two loci displayed similar Hop1 occupancy levels, and VDE-induced crossovers were similarly MutLγ-dependent. We suggest that meiotic and mitotic recombination pathways coexist within meiotic cells, and that features of meiotic chromosome structure determine whether one or the other predominates in different regions.

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1902440116 ◽

2019 ◽

Vol 116 (37) ◽

pp. 18423-18428 ◽

Cited By ~ 20

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.

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