Nonsense mutation at Tyr-4046 in the DNA-dependent protein kinase catalytic subunit of severe combined immune deficiency mice.
The severe combined immune deficiency (SCID) mouse was reported as an animal model for human immune deficiency. Through the course of several studies, the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) gene came to be considered a candidate for the SCID-responsible gene. We isolated an ORF of the murine DNA-PKcs gene from SCID mice and their parent strain C.B-17 mice and determined the DNA sequences. The ORF of the murine DNA-PKcs gene contained 4128-aa residues and had 78.9% homology with the human DNA-PKcs gene. A particularly important finding is that a T to A transversion results in the substitution of termination codon in SCID mice for the Tyr-4046 in C.B-17 mice. No other mutation was detected in the ORF of the gene. The generality of this transversion was confirmed using four individual SCID and wild-type mice. The substitution took place in the phosphatidylinositol 3-kinase domain, and the mutated gene encodes the truncated products missing 83 residues of wild-type DNA-PKcs products. Furthermore, the quantity of DNA-PKcs transcript in wild-type and SCID cells was almost equal. These observations indicate that the DNA-PKcs gene is the SCID-responsible gene itself and that the detected mutation leads to the SCID aberration.
Araki
R
R
National Institute of Radiological Sciences, Inage-ku, Chiba, Japan.
Fujimori
A
A
Hamatani
K
K
Mita
K
K
Saito
T
T
Mori
M
M
Fukumura
R
R
Morimyo
M
M
Muto
M
M
Itoh
M
M
Tatsumi
K
K
Abe
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003062:Codon; D017931:DNA Primers; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D015870:Gene Expression; D015723:Gene Library; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D008815:Mice, Inbred Strains; D016513:Mice, SCID / Q000235:genetics*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D016366:Open Reading Frames; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000737:chemistry; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014443:Tyrosine
D003062:Codon; D017931:DNA Primers; D051747:DNA-Activated Protein Kinase; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D019869:Phosphatidylinositol 3-Kinases; D017853:Phosphotransferases (Alcohol Group Acceptor); D017346:Protein Serine-Threonine Kinases; D014443:Tyrosine; C497263:PRKDC protein, human; C497264:Prkdc protein, mouse