scholarly journals Bivalent Formation 1, a plant-conserved gene, encodes an OmpH/coiled-coil motif-containing protein required for meiotic recombination in rice

2017 ◽  
Vol 68 (9) ◽  
pp. 2163-2174 ◽  
Author(s):  
Lian Zhou ◽  
Jingluan Han ◽  
Yuanling Chen ◽  
Yingxiang Wang ◽  
Yao-Guang Liu
Keyword(s):  
Meiotic Recombination ◽  
Coiled Coil ◽  
Bivalent Formation ◽  
Conserved Gene

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

eLife ◽  
2019 ◽  
Vol 8 ◽  
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.

scholarly journals ZHP-3 Acts at Crossovers to Couple Meiotic Recombination with Synaptonemal Complex Disassembly and Bivalent Formation in C. elegans

PLoS Genetics ◽  
2008 ◽  
Vol 4 (10) ◽  
pp. e1000235 ◽  
Author(s):  
Needhi Bhalla ◽  
David J. Wynne ◽  
Verena Jantsch ◽  
Abby F. Dernburg
Keyword(s):  
Synaptonemal Complex ◽  
Meiotic Recombination ◽  
C Elegans ◽  
Bivalent Formation

scholarly journals Fanconi anemia ortholog FANCM regulates meiotic crossover distribution in plants

2021 ◽  
Author(s):  
Xiang Li ◽  
Mingsen Yu ◽  
Pablo Bolaños-Villegas ◽  
Jun Zhang ◽  
Di'an Ni ◽  
...  
Keyword(s):  
Fanconi Anemia ◽  
Meiotic Recombination ◽  
Pollen Viability ◽  
Complementation Group ◽  
Class I ◽  
Great Promise ◽  
Strand Breaks ◽  
Meiotic Chromosomes ◽  
Brassica Spp ◽  
Bivalent Formation

Abstract Meiotic recombination increases genetic diversity and manipulation of its frequency and distribution holds great promise in crop breeding. In Arabidopsis thaliana, FANCM (a homolog of mammalian Fanconi anemia complementation group M) suppresses recombination and its function seems conserved in other species including the rosids Brassica spp. and pea (Pisum sativum), and the monocot rice (Oryza sativa). To examine the role of FANCM during meiotic recombination in lettuce (Lactuca sativa, an asterid), we characterized the function of lettuce LsFANCM and found that it can functionally substitute for AtFANCM in transgenic Arabidopsis plants. Moreover, three independent CRISPR/Cas9-edited lettuce Lsfancm mutants showed reduced pollen viability and seed setting. Unexpectedly, analyses of chromosome behavior revealed that 77.8% of Lsfancm meiocytes exhibited univalents. The normal formation of double-strand breaks in DNA and the discontinuous assembly of synaptonemal complex in Lsfancm mutants supports the hypothesis that LsFANCM might be dispensable for the initiation of meiotic recombination but required for normal synapsis. Furthermore, the frequency of lettuce HEI10 (Human Enhancer of Invasion 10) foci, a marker for Class-I crossovers (COs), was similar between wild-type (WT) and Lsfancm. Strikingly, the distribution of LsHEI10 foci and chiasmata in Lsfancm meiotic chromosomes was markedly different from the WT. A similar alteration in the distribution of Class-I COs was also observed in the Arabidopsis Atfancm mutant. Taken together, these results demonstrate that FANCM is important for shaping the distribution of meiotic Class-I COs in plants, and reveal an evolutionarily divergent role for FANCM in meiotic bivalent formation between Arabidopsis and lettuce.

scholarly journals A cryptic BRCA2 repeated motif binds to HSF2BP oligomers with no impact on meiotic recombination

2020 ◽  
Author(s):  
Rania Ghouil ◽  
Simona Miron ◽  
Lieke Koornneef ◽  
Jasper Veerman ◽  
Maarten W. Paul ◽  
...  
Keyword(s):  
Meiotic Recombination ◽  
Coiled Coil ◽  
Double Strand Breaks ◽  
Strand Breaks ◽  
High Affinity ◽  
Functional Consequences ◽  
Direct Binding ◽  
Affinity Interaction ◽  
Repeated Motif

AbstractBRCA2 plays a prominent role in meiotic homologous recombination (HR). Loss of BRCA2 or several of its meiotic partners causes fertility defects. One of these partners, HSF2BP, was recently discovered as expressed physiologically in germline and ectopically produced in cancer cells. It has an N-terminal coiled coil motif involved in direct binding to the protein BRME1, and both HSF2BP and BRME1 are essential for meiotic HR during spermatogenesis. It also interacts through its C-terminal Armadillo (ARM) domain with a conserved region of BRCA2 of unknown function. We analyzed the structural properties and functional consequences of the BRCA2-HSF2BP interaction and tested the emerging model of its involvement in meiosis. We solved the crystal structure of the complex between the BRCA2 fragment that is disordered in solution and the HSF2BP dimeric ARM domain. This revealed two previously unrecognized BRCA2 repeats that each interact with one ARM monomer from two different dimers. BRCA2 binding triggers ARM tetramerization, resulting in a complex containing two BRCA2 fragments connecting two ARM dimers. The 3D structures of the BRCA2 repeats are superimposable, revealing conserved contacts between the BRCA2 residues defining the repeats and the HSF2BP residues lining the groove of the ARM. This large interface is responsible for the nanomolar affinity of the interaction, significantly stronger than any other measured interaction involving BRCA2. Deleting exon 12 from Brca2, encoding the first repeat, disrupted BRCA2 binding to HSF2BP in vitro and in cells. However, Brca2Δ12/Δ12 mice with the same deletion were fertile and did not show any meiotic defects, contrary to the prediction from the model positing that HSF2BP acts as a meiotic localizer of BRCA2. We conclude that the high-affinity interaction between BRCA2 and HSF2BP and the resulting HSF2BP oligomerization are not required for RAD51 and DMC1 recombinase localization to meiotic double strand breaks and for productive meiotic HR.

scholarly journals The Formation of Bivalents and the Control of Plant Meiotic Recombination

2021 ◽  
Vol 12 ◽  
Author(s):  
Yared Gutiérrez Pinzón ◽  
José Kenyi González Kise ◽  
Patricia Rueda ◽  
Arnaud Ronceret
Keyword(s):  
Meiotic Recombination ◽  
Meiotic Division ◽  
Strand Break ◽  
Crop Plants ◽  
Meiotic Spindle ◽  
Axis Formation ◽  
Homologous Chromosomes ◽  
Bivalent Formation ◽  
Reductional Division ◽  
Made In

During the first meiotic division, the segregation of homologous chromosomes depends on the physical association of the recombined homologous DNA molecules. The physical tension due to the sites of crossing-overs (COs) is essential for the meiotic spindle to segregate the connected homologous chromosomes to the opposite poles of the cell. This equilibrated partition of homologous chromosomes allows the first meiotic reductional division. Thus, the segregation of homologous chromosomes is dependent on their recombination. In this review, we will detail the recent advances in the knowledge of the mechanisms of recombination and bivalent formation in plants. In plants, the absence of meiotic checkpoints allows observation of subsequent meiotic events in absence of meiotic recombination or defective meiotic chromosomal axis formation such as univalent formation instead of bivalents. Recent discoveries, mainly made in Arabidopsis, rice, and maize, have highlighted the link between the machinery of double-strand break (DSB) formation and elements of the chromosomal axis. We will also discuss the implications of what we know about the mechanisms regulating the number and spacing of COs (obligate CO, CO homeostasis, and interference) in model and crop plants.

TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum

2019 ◽  
Vol 476 (21) ◽  
pp. 3241-3260
Author(s):  
Sindhu Wisesa ◽  
Yasunori Yamamoto ◽  
Toshiaki Sakisaka
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Mammalian Cells ◽  
Coiled Coil ◽  
Transmembrane Domains ◽  
Domain Family ◽  
Coiled Coil Domain ◽  
U2os Cells ◽  
Er Membrane

The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. In this study, we report TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.

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