J 2021

Caenorhabditis elegans RMI2 functional homolog-2 (RMIF-2) and RMI1 (RMH-1) have both overlapping and distinct meiotic functions within the BTR complex

VELKOVA, M., Nicola SILVA, M. R. DELLO STRITTO, A. SCHLEIFFER, P. BARRAUD et. al.

Základní údaje

Originální název

Caenorhabditis elegans RMI2 functional homolog-2 (RMIF-2) and RMI1 (RMH-1) have both overlapping and distinct meiotic functions within the BTR complex

Autoři

VELKOVA, M., Nicola SILVA (380 Itálie, domácí), M. R. DELLO STRITTO, A. SCHLEIFFER, P. BARRAUD, M. HARTL a V. JANTSCH (garant)

Vydání

PLoS Genetics, San Francisco, Public Library of Science, 2021, 1553-7404

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10603 Genetics and heredity

Stát vydavatele

Spojené státy

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 6.020

Kód RIV

RIV/00216224:14110/21:00119145

Organizační jednotka

Lékařská fakulta

UT WoS

000674293300003

Klíčová slova anglicky

Caenorhabditis elegans; RMIF-2; RMH-1; BTR complex

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 19. 8. 2021 12:33, Mgr. Tereza Miškechová

Anotace

V originále

Author summary Bloom syndrome is caused by mutations in proteins of the BTR complex (consisting of the Bloom helicase, topoisomerase 3, and the RMI1 and RMI2 scaffolding proteins) and the clinical characteristics are growth deficiency, short stature, skin photosensitivity, and increased cancer predisposition. At the cellular level, characteristic features are the presence of increased sister chromatid exchange on chromosomes; unresolved DNA recombination intermediates that eventually cause genome instability; and erroneous DNA repair by heterologous recombination (recombination between non-identical sequences, extremely rare in wild type animals), which can trigger translocations and chromosomal rearrangements. Identification of the Caenorhabditis elegans ortholog of RMI2 (called RMIF-2) allowed us to compare heterologous recombination in the germline of mutants of various BTR complex proteins. The heterologous recombination rate was several fold lower in rmif-2 mutants than in mutants of rmh-1 and him-6 (worm homologs of RMI1 and the Bloom helicase, respectively). Nevertheless, many phenotypic features point at RMIF-2 working together with RMH-1. If these germline functions of RMI2/RMIF-2 are conserved in humans, this might mean that individuals with RMI2 mutations have a lower risk of translocations and genome rearrangements than those with mutations in the other BTR complex genes. Homologous recombination is a high-fidelity repair pathway for DNA double-strand breaks employed during both mitotic and meiotic cell divisions. Such repair can lead to genetic exchange, originating from crossover (CO) generation. In mitosis, COs are suppressed to prevent sister chromatid exchange. Here, the BTR complex, consisting of the Bloom helicase (HIM-6 in worms), topoisomerase 3 (TOP-3), and the RMI1 (RMH-1 and RMH-2) and RMI2 scaffolding proteins, is essential for dismantling joint DNA molecules to form non-crossovers (NCOs) via decatenation. In contrast, in meiosis COs are essential for accurate chromosome segregation and the BTR complex plays distinct roles in CO and NCO generation at different steps in meiotic recombination. RMI2 stabilizes the RMI1 scaffolding protein, and lack of RMI2 in mitosis leads to elevated sister chromatid exchange, as observed upon RMI1 knockdown. However, much less is known about the involvement of RMI2 in meiotic recombination. So far, RMI2 homologs have been found in vertebrates and plants, but not in lower organisms such as Drosophila, yeast, or worms. We report the identification of the Caenorhabditis elegans functional homolog of RMI2, which we named RMIF-2. The protein shows a dynamic localization pattern to recombination foci during meiotic prophase I and concentration into recombination foci is mutually dependent on other BTR complex proteins. Comparative analysis of the rmif-2 and rmh-1 phenotypes revealed numerous commonalities, including in regulating CO formation and directing COs toward chromosome arms. Surprisingly, the prevalence of heterologous recombination was several fold lower in the rmif-2 mutant, suggesting that RMIF-2 may be dispensable or less strictly required for some BTR complex-mediated activities during meiosis.

Návaznosti

GA20-08819S, projekt VaV
Název: Pochopení úlohy PARG při podpoře tvorby a oprav dvouřetězcových zlomů DNA v meióze
Investor: Grantová agentura ČR, Pochopení úlohy PARG při podpoře tvorby a oprav dvouřetězcových zlomů DNA v meióze