A conserved degradation signal regulates RAG-2 accumulation during cell division and links V(D)J recombination to the cell cycle.
The proteins RAG-1 and RAG-2 are essential for initiation of V(D)J recombination. In dividing cells, RAG-2 accumulates during G1 and is undetectable during the S and G2/M cell cycle phases. A conserved degradation signal, including an essential CDK phosphorylation site at Thr-490, regulates RAG-2 accumulation during cell division and links V(D)J recombination to the cell cycle. Mutations within this signal abolish periodic degradation of RAG-2 protein in dividing cells. In mice expressing endogenous or wild-type transgenic RAG-2, V(D)J recombination intermediates accumulate preferentially in G0/G1 thymocytes; this restriction is relieved by mutation of Thr-490 to alanine (T490A). Thus, periodic destruction of RAG-2 protein couples V(D)J recombination to cell cycle phase. Using transgenic mice expressing the T490A RAG-2 mutant and a functional T cell receptor beta chain, we demonstrate that coupling of V(D)J recombination to the cell cycle is not essential for enforcement of allelic exclusion.
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Department of Molecular Biology and Genetics, John Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Dordai
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D000595:Amino Acid Sequence; D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D004268:DNA-Binding Proteins; D005260:Female; D005803:Genes, Immunoglobulin; D006207:Half-Life; D006801:Humans; D007128:Immunoglobulin Fragments / Q000235:genetics*; D007133:Immunoglobulin Joining Region / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins; D010455:Peptides / Q000378:metabolism; D010507:Periodicity; D010766:Phosphorylation; D011506:Proteins / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell; D011995:Recombination, Genetic; D013329:Structure-Activity Relationship; D013950:Thymus Gland / Q000166:cytology / Q000378:metabolism
D004268:DNA-Binding Proteins; D007128:Immunoglobulin Fragments; D007133:Immunoglobulin Joining Region; D007135:Immunoglobulin Variable Region; D009687:Nuclear Proteins; D010455:Peptides; D011506:Proteins; C499311:RAG2 protein, human; C499308:Rag2 protein, mouse; D011948:Receptors, Antigen, T-Cell; C064655:V(D)J recombination activating protein 2; D018844:Cyclin-Dependent Kinases