Franca, Monica MCondezo, Yazmine BElzaiat, MaëvaFelipe-Medina, NataliaSánchez-Sáez, FernandoMuñoz, SergioSainz-Urruela, RaquelMartín-Hervás, M RosarioGarcía-Valiente, RodrigoSánchez-Martín, Manuel AAstudillo, AuroraMendez, JuanLlano, ElenaVeitia, Reiner AMendonca, Berenice BPendás, Alberto M2024-12-042024-12-042022-12Cell Death Differ . 2022 Dec;29(12):2347-2361https://hdl.handle.net/20.500.12105/25853Primary ovarian insufficiency (POI) causes female infertility by abolishing normal ovarian function. Although its genetic etiology has been extensively investigated, most POI cases remain unexplained. Using whole-exome sequencing, we identified a homozygous variant in RAD51B -(c.92delT) in two sisters with POI. In vitro studies revealed that this variant leads to translation reinitiation at methionine 64. Here, we show that this is a pathogenic hypomorphic variant in a mouse model. Rad51b mice exhibited meiotic DNA repair defects due to RAD51 and HSF2BP/BMRE1 accumulation in the chromosome axes leading to a reduction in the number of crossovers. Interestingly, the interaction of RAD51B-c.92delT with RAD51C and with its newly identified interactors RAD51 and HELQ was abrogated or diminished. Repair of mitomycin-C-induced chromosomal aberrations was impaired in RAD51B/Rad51b-c.92delT human and mouse somatic cells in vitro and in explanted mouse bone marrow cells. Accordingly, Rad51b-c.92delT variant reduced replication fork progression of patient-derived lymphoblastoid cell lines and pluripotent reprogramming efficiency of primary mouse embryonic fibroblasts. Finally, Rad51b mice displayed increased incidence of pituitary gland hyperplasia. These results provide new mechanistic insights into the role of RAD51B not only in meiosis but in the maintenance of somatic genome stability.The authors thank the patients and their family for participating in this study. The authors are grateful to LIM42 and SELA teams for providing technical assistance. We thank also to Dr. Alex N. Zelensky for his useful comments and to Isabel Ramos and Marina Jimenez-Ruiz (Molecular Mechanisms Program, Centro de Investigacion del Cancer) for their help in genotyping and intraperitoneal injections of the mice used in this study. We also are indebted to Maria Daniela Corte Torres (Biobanco of the Principado de Asturias/Instituto de Investigacion Sanitaria del Principado de Asturias) for her technical assistance. This work was supported by the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) Grant 2014/14231-0 (to MMF); FAPESP Grant 2013/02162-8, Nucleo de Estudos e Terapia Celular e Molecular (NETCEM), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico Grant 303002/20166 (to BBM); and FAPESP Grant 2014/50137-5 (to SELA). This work was supported by MINECO (PID2020-120326RB-I00) and by Junta de Castilla y Leon (CSI239P18 and CSI148P20). NFM, FSS, and MRMH are supported by European Social Fund/JCyLe grants (EDU/310/2015, EDU/556/2019 and EDU/1992/2020). YBC and RSU are funded by a grant from MINECO (BS-2015-073993 and BFU2017-89408-R). Experiments performed at CNIO were supported by grant PID2019-106707-RB to JM, co-sponsored by EU ERDF funds. SM was supported by an international postdoctoral contract "CNIO Friends". The proteomic analysis was performed in the Proteomics Facility of Centro de Investigacion del Cancer, Salamanca, Grant PRB3(IPT17/0019 -ISCIII-SGEFI/ERDF). CIC-IBMCC is supported by the Programa de Apoyo a Planes Estrategicos de Investigacion de Estructuras de Investigacion de Excelencia cofunded by the Castilla-Leon autonomous government and the European Regional Development Fund (CLC-2017-01). Veitia's Lab is supported by the University of Paris and the Centre National de la Recherche Scientifique.engVoRhttp://creativecommons.org/licenses/by-nc-nd/4.0/GENOME-WIDE ASSOCIATIONHOMOLOGOUS RECOMBINATIONDNAREPAIRGENEMUTATIONSCANCERLETHALITYIMPACTAttribution-NonCommercial-NoDerivatives 4.0 International3562430829122347-2361Cell Death Differhttps://pmc.ncbi.nlm.nih.gov/articles/PMC9751091/open access