P31 ^comet , a member of the synaptonemal complex, participates in meiotic DSB formation in rice

Abstract

The human mitotic arrest-deficient 2 (Mad2) binding protein p31 comet participates in the spindle checkpoint and coordinates cell cycle events in mitosis although its function in meiosis remains unknown in all organisms. Here, we reveal P31 comet as a synaptonemal complex (SC) protein in rice (Oryza sativa L.). In p31 comet , homologous pairing and synapsis are eliminated, leading to the homologous nondisjunction and complete sterility. The failure in loading of histone H2AX phosphorylation (γH2AX) in p31 comet , together with the suppressed chromosome fragmentation in rice completion of meiotic recombination 1 (com1) p31 comet and radiation sensitive 51c (rad51c) p31 comet double mutants, indicates that P31 comet plays an essential role in double-strand break (DSB) formation. Interestingly, the dynamic colocalization pattern between P31 comet and ZEP1 (a transverse filament protein of SC) by immunostaining, as well as the interaction between P31 comet and CENTRAL REGION COMPONENT 1 (CRC1) in yeast two-hybrid assays, suggests possible involvement of P31 comet in SC installation. Together, these data indicate that P31 comet plays a key role in DSB formation and SC installation, mainly through its cooperation with CRC1.uring meiosis, homologous recombination plays a crucial role in ensuring faithful and precise chromosome segregation, as well as in diversifying genetic information. Meiotic recombination is induced by the programmed formation of DNA double-strand breaks (DSBs), catalyzed by Spo11, a functional homolog of subunit A of an archaeal topoisomerase (TopoVIA) (1). In Saccharomyces cerevisiae, nine associated proteins, including meiotic recombination 11 (Mre11), radiation sensitive 50 (Rad50), X-ray sensitive 2 (Xrs2), superkiller 8 (Ski8), Rec102, Rec104, Rec114, meiosis-specific 4 (Mei4), and Mer2, are required for facilitating Spo11's catalytic reaction (2). In Schizosaccharomyces pombe, seven DSB formation-related proteins were identified (3). Rec6 has been recognized as an essential component for ensuring the meiotic DSB formation, and it forms a complex with Rec12 and Rec14, the orthologs of Spo11 and Ski8, respectively (4). Furthermore, the Mde2 protein, which lacks an ortholog in S. cerevisiae, is also required for DSB formation (5). Nevertheless, Rad50, Mre11, and Xrs2 orthologs are dispensable for DSB formation in S. pombe, as well as in mice and plants, but they are required for meiotic DSB processing (6). In mice, except for the conserved protein Spo11, Mei4 and Rec114 were also identified as key components involved in DSB formation (7). In addition, Mei1 was recognized as a recombination related factor, without an ortholog in S. cerevisiae or S. pombe (8). Recently, mouse TOPOVIBL protein was identified to form the complex with Spo11 and take part in meiotic DSB formation (9).In plants, the Arabidopsis AtSPO11-1, AtSPO11-2, and AtSPO11-3 share sequence similarity with other Spo11/topo VIA proteins. AtSPO11-1 and AtSPO11-2, as subunits of a heterodimer, are essential for DSB formation whereas A...

The AAA + ATP ase TRIP 13 remodels HORMA domains through N‐terminal engagement and unfolding

“…The key aspect of Pch2/TRIP13 function in meiosis is that it removes meiotic HORMADs specifically from synapsed chromosomes/regions, serving as a feedback mechanism controlling DNA breakage and crossover levels on a per‐chromosome basis (Borner et al , ; Joshi et al , ; Wojtasz et al , ; Thacker et al , ; Lambing et al , ; Vader, ). A recent finding that in rice, p31 comet is localized to the synaptonemal complex suggests that this protein might also be involved in the recognition and removal of meiotic HORMADs, and in dictating the specificity for synapsed chromosome regions (Ji et al , ). We have so far been unable to demonstrate direct interactions between mammalian p31 comet and meiotic HORMADs in vitro , however (data not shown), suggesting either that this mechanism is not highly conserved or involves additional factors.…”

Understanding and Manipulating Meiotic Recombination in Plants

“…In addition, rice (Oryza sativa) CRC1, which shares similarities with PCH2 in Arabidopsis and S. cerevisiae was shown to be required for DSB formation (Miao et al, 2013), but there is no detectable change in DSB number in pch2 mutants in Arabidopsis . Interestingly, P31 comet was identified recently as a protein interacting with rice CRC1 (Ji et al, 2016). Similar to CRC1, P31 comet also is essential for DSB formation in rice.…”

Engineering meiotic recombination pathways in rice

“…In yeast, the formation of SPO11‐induced DSBs involves at least nine other proteins (Mre11, Rad50, Xrs2, Ski8, Rec102, Rec104, Rec114, Mei4 and Mer2), some but not all identified yet across kingdoms. In plants, seven proteins have been found required for meiotic DSB formation: AtPRD1, AtPRD2, AtPRD3/PAIR1, AtDFO, OsCRC1, OsSDS and OsP31 COMET (Ji et al , ; Miao et al , ; De Muyt et al , ; De Muyt et al , ; Nonomura et al , ; Wu et al , ; Zhang et al , ). AtPRD1 and AtPRD2 are the likely orthologues of mouse Mei1 and yeast and mouse Mei4, while AtPRD3 (PAIR1 in rice) and OsCRC1 might be plant‐specific.…”

“…Whereas mutation in OsSDS appeared to abolish DSB formation in rice (Wu et al, ), this meiosis‐specific cyclin‐like protein is required for DMC1‐mediated DSB repair but not for DSB formation in Arabidopsis (De Muyt et al, ). P31 COMET that interacts with CRC1 is an additional protein essential for DSB formation in rice (Ji et al , ).…”