V(D)J recombination in Ku86-deficient mice: distinct effects on coding, signal, and hybrid joint formation.
Ku, a heterodimer of 70 and 86 kDa subunits, plays a critical but poorly understood role in V(D)J recombination. Although Ku86-deficient mice are defective in coding and signal joint formation, rare recombination products have been detected by PCR. Here, we report nucleotide sequences of 99 junctions from Ku86-deficient mice. Over 90% of the coding joints, but not signal or hybrid joints, exhibit short sequence homologies, indicating that homology is required to join coding ends in the absence of Ku86. Our results suggest that Ku86 may normally have distinct functions in the formation of these different types of junctions. Furthermore, Ku86(-/-) joints are unexpectedly devoid of N-region diversity, suggesting a novel role for Ku in the addition of N nucleotides by terminal deoxynucleotidyl transferase.
Bogue
M A
MA
Department of Microbiology and Immunology, Baylor College of Medicine, Houston, Texas 77030, USA.
Wang
C
C
Zhu
C
C
Roth
D B
DB
D000818:Animals; D034961:Antigens, Nuclear; D001483:Base Sequence; D001854:Bone Marrow Cells; D004265:DNA Helicases; D004253:DNA Nucleotidylexotransferase / Q000378:metabolism; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000502:physiology*; D015321:Gene Rearrangement; D015329:Gene Rearrangement, T-Lymphocyte; D007143:Immunoglobulin Heavy Chains / Q000235:genetics / Q000378:metabolism; D007133:Immunoglobulin Joining Region / Q000235:genetics / Q000378:metabolism; D000072200:Ku Autoantigen; D051379:Mice; D016513:Mice, SCID; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000502:physiology*; D016133:Polymerase Chain Reaction; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic; D013234:Stem Cells / Q000378:metabolism; D014157:Transcription Factors / Q000172:deficiency / Q000502:physiology*
D034961:Antigens, Nuclear; D004268:DNA-Binding Proteins; D007143:Immunoglobulin Heavy Chains; D007133:Immunoglobulin Joining Region; D009687:Nuclear Proteins; D016692:Receptors, Antigen, T-Cell, gamma-delta; D014157:Transcription Factors; D004253:DNA Nucleotidylexotransferase; D004265:DNA Helicases; C106893:XRCC5 protein, human; C000606512:Xrcc5 protein, mouse; C000606509:Xrcc6 protein, human; C000606510:Xrcc6 protein, mouse; D000072200:Ku Autoantigen