title: A DNA-PKcs mutation in a radiosensitive T-B- SCID patient inhibits Artemis activation and nonhomologous end-joining.
abstract: Radiosensitive T-B- severe combined immunodeficiency (RS-SCID) is caused by defects in the nonhomologous end-joining (NHEJ) DNA repair pathway, which results in failure of functional V(D)J recombination. Here we have identified the first human RS-SCID patient to our knowledge with a DNA-PKcs missense mutation (L3062R). The causative mutation did not affect the kinase activity or DNA end-binding capacity of DNA-PKcs itself; rather, the presence of long P-nucleotide stretches in the immunoglobulin coding joints indicated that it caused insufficient Artemis activation, something that is dependent on Artemis interaction with autophosphorylated DNA-PKcs. Moreover, overall end-joining activity was hampered, suggesting that Artemis-independent DNA-PKcs functions were also inhibited. This study demonstrates that the presence of DNA-PKcs kinase activity is not sufficient to rule out a defect in this gene during diagnosis and treatment of RS-SCID patients. Further, the data suggest that residual DNA-PKcs activity is indispensable in humans.
authors.affiliation: Department of Immunology, Erasmus Medical Center, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Mirjam
authors.initials: M
authors.lastname: van der Burg
authors.forename: Hanna
authors.initials: H
authors.lastname: Ijspeert
authors.forename: Nicole S
authors.initials: NS
authors.lastname: Verkaik
authors.forename: Tuba
authors.initials: T
authors.lastname: Turul
authors.forename: Wouter W
authors.initials: WW
authors.lastname: Wiegant
authors.forename: Keiko
authors.initials: K
authors.lastname: Morotomi-Yano
authors.forename: Pierre-Olivier
authors.initials: PO
authors.lastname: Mari
authors.forename: Ilhan
authors.initials: I
authors.lastname: Tezcan
authors.forename: David J
authors.initials: DJ
authors.lastname: Chen
authors.forename: Malgorzata Z
authors.initials: MZ
authors.lastname: Zdzienicka
authors.forename: Jacques J M
authors.initials: JJ
authors.lastname: van Dongen
authors.forename: Dik C
authors.initials: DC
authors.lastname: van Gent
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002675:Child, Preschool; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000235:genetics / Q000378:metabolism; D004252:DNA Mutational Analysis; D004260:DNA Repair; D051747:DNA-Activated Protein Kinase / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins; D004720:Endonucleases; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology / Q000528:radiation effects; D005838:Genotype; D006801:Humans; D007223:Infant; D008297:Male; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism*; D010375:Pedigree; D011836:Radiation Tolerance; D011995:Recombination, Genetic; D016415:Sequence Alignment; D016511:Severe Combined Immunodeficiency / Q000175:diagnosis / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D051747:DNA-Activated Protein Kinase; C497263:PRKDC protein, human; C426344:DCLRE1C protein, human; D004720:Endonucleases; D011088:DNA Ligases; D000072481:DNA Ligase ATP