biostudies-literature00560Chen CCTore Nilssons StiftelseJeanssons StiftelserVetenskapsrådetALF Medicin StockholmHudfondenNational Institutes of HealthLeukemia & Lymphoma SocietySvenska Sällskapet förr Medicinsk Forskninge20201708https://www.ebi.ac.uk/biostudies/studies/S-EPMC8155808biostudies-literatureUnknown218(8)A whole-genome CRISPR/Cas9 screen identified ATP2A2, the gene encoding the Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) 2 protein, as being important for V(D)J recombination. SERCAs are ER transmembrane proteins that pump Ca2+ from the cytosol into the ER lumen to maintain the ER Ca2+ reservoir and regulate cytosolic Ca2+-dependent processes. In preB cells, loss of SERCA2 leads to reduced V(D)J recombination kinetics due to diminished RAG-mediated DNA cleavage. SERCA2 deficiency in B cells leads to increased expression of SERCA3, and combined loss of SERCA2 and SERCA3 results in decreased ER Ca2+ levels, increased cytosolic Ca2+ levels, reduction in RAG1 and RAG2 gene expression, and a profound block in V(D)J recombination. Mice with B cells deficient in SERCA2 and humans with Darier disease, caused by heterozygous ATP2A2 mutations, have reduced numbers of mature B cells. We conclude that SERCA proteins modulate intracellular Ca2+ levels to regulate RAG1 and RAG2 gene expression and V(D)J recombination and that defects in SERCA functions cause lymphopenia.The Journal of experimental medicineSarco/endoplasmic reticulum Ca2+-ATPase (SERCA) activity is required for V(D)J recombination.PMC8155808R01 CA95641R01 AI 032524R01 AI047829R01 DK097441R37 NS036942R01 AI074953Farrell RJLiu CCWikstrom JDBeilinson HAChen CCTyler JKde Juan-Sanz JChatila TASleckman BPCurman PCharbonnier LMChen BRSchatz DGRyan TAWang YKajimura SBrecht RM56falseSarco/endoplasmic reticulum Ca2+-ATPase (SERCA) activity is required for V(D)J recombination.A whole-genome CRISPR/Cas9 screen identified ATP2A2, the gene encoding the Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) 2 protein, as being important for V(D)J recombination. SERCAs are ER transmembrane proteins that pump Ca2+ from the cytosol into the ER lumen to maintain the ER Ca2+ reservoir and regulate cytosolic Ca2+-dependent processes. In preB cells, loss of SERCA2 leads to reduced V(D)J recombination kinetics due to diminished RAG-mediated DNA cleavage. SERCA2 deficiency in B cells leads to increased expression of SERCA3, and combined loss of SERCA2 and SERCA3 results in decreased ER Ca2+ levels, increased cytosolic Ca2+ levels, reduction in RAG1 and RAG2 gene expression, and a profound block in V(D)J recombination. Mice with B cells deficient in SERCA2 and humans with Darier disease, caused by heterozygous ATP2A2 mutations, have reduced numbers of mature B cells. We conclude that SERCA proteins modulate intracellular Ca2+ levels to regulate RAG1 and RAG2 gene expression and V(D)J recombination and that defects in SERCA functions cause lymphopenia.2021-01-01T00:00:00Z2021 Aug2024-02-15T06:32:37.13Z2022-02-11T15:51:44.389ZS-EPMC81558083403367610.1084/jem.20201708