COSA-1 mediated pro-crossover complex formation promotes meiotic crossing over in C. elegans.
Nucleic Acids Res
; 52(8): 4375-4392, 2024 May 08.
Article
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| MEDLINE
| ID: mdl-38412290
ABSTRACT
Accurate chromosome segregation during meiosis requires the establishment of at least one crossover (CO) between each pair of homologous chromosomes. CO formation depends on a group of conserved pro-CO proteins, which colocalize at CO-designated sites during late meiotic prophase I. However, it remains unclear whether these pro-CO proteins form a functional complex and how they promote meiotic CO formation in vivo. Here, we show that COSA-1, a key component required for CO formation, interacts with other pro-CO factors, MSH-5 and ZHP-3, via its N-terminal disordered region. Point mutations that impair these interactions do not affect CO designation, but they strongly hinder the accumulation of COSA-1 at CO-designated sites and result in defective CO formation. These defects can be partially bypassed by artificially tethering an interaction-compromised COSA-1 derivate to ZHP-3. Furthermore, we revealed that the accumulation of COSA-1 into distinct foci is required to assemble functional 'recombination nodules'. These prevent early CO-designated recombination intermediates from being dismantled by the RTEL-1 helicase and protect late recombination intermediates, such as Holliday junctions, until they are resolved by CO-specific resolvases. Altogether, our findings provide insight into COSA-1 mediated pro-CO complex assembly and its contribution to CO formation.
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1
Banco de datos:
MEDLINE
Asunto principal:
Intercambio Genético
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Proteínas de Caenorhabditis elegans
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Proteínas de Unión al ADN
Límite:
Animals
Idioma:
En
Año:
2024
Tipo del documento:
Article