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VprBP binds full‐length RAG1 and is required for B‐cell development and V(D)J recombination fidelity
Author(s) -
Kassmeier Michele D,
Mondal Koushik,
Palmer Victoria L,
Raval Prafulla,
Kumar Sushil,
Perry Greg A,
Anderson Dirk K,
Ciborowski Pawel,
Jackson Sarah,
Xiong Yue,
Swanson Patrick C
Publication year - 2012
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2011.455
Subject(s) - biology , ubiquitin ligase , recombination activating gene , microbiology and biotechnology , dna ligase , v(d)j recombination , cullin , protein subunit , rag2 , ubiquitin , genetics , dna , recombination , gene
The N‐terminus of full‐length RAG1, though dispensable for RAG1/2 cleavage activity, is required for efficient V(D)J recombination. This region supports RING E3 ubiquitin ligase activity in vitro , but whether full‐length RAG1 functions as a single subunit or a multi‐subunit E3 ligase in vivo is unclear. We show the multi‐subunit cullin RING E3 ligase complex VprBP/DDB1/Cul4A/Roc1 associates with full‐length RAG1 through VprBP. This complex is assembled into RAG protein–DNA complexes, and supports in‐vitro ubiquitylation activity that is insensitive to RAG1 RING domain mutations. Conditional B lineage‐specific VprBP disruption arrests B‐cell development at the pro‐B‐to‐pre‐B cell transition, but this block is bypassed by expressing rearranged immunoglobulin transgenes. Mice with a conditional VprBP disruption show modest reduction of D–J H rearrangement, whereas V H –DJ H and V κ –J κ rearrangements are severely impaired. D–J H coding joints from VprBP ‐insufficent mice show longer junctional nucleotide insertions and a higher mutation frequency in D and J segments than normal. These data suggest full‐length RAG1 recruits a cullin RING E3 ligase complex to ubiquitylate an unknown protein(s) to limit error‐prone repair during V(D)J recombination.