An intragenic deletion of nuclear localization signal-1 of p53 tumor suppressor gene results in loss of apoptosis in murine fibroblasts.
We established mouse lines containing either full-length wild-type p53 or nuclear localization signal-I (NLS-I) deleted p53 to study the role of NLS-I in p53 translocation and function. Induction of apoptosis in response to DNA damage, a primary function of p53, was tested in these cell lines. After exposure to gamma-ionizing radiation or hydrogen peroxide, DNA ladders and labeling of nucelosomal fragments were detected in cells with wild-type p53 gene, but not in p53 null cells or NLS-I deleted cells, suggesting that the NLS-I of p53 protein is necessary for apoptosis. Analysis of p53 protein from subcellular fractions indicated that NLS-I deprived p53 remained in the cytoplasmic fraction, which may explain why NLS-I deleted p53 failed to induce apoptosis.
Zhao
W
W
Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Science, Research Triangle Park, NC 27709, USA.
He
C
C
Rotter
V
V
Merrick
B A
BA
Selkirk
J K
JK
D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D015153:Blotting, Western; D002460:Cell Line; D002470:Cell Survival / Q000235:genetics / Q000528:radiation effects; D053938:DNA Fragmentation; D004587:Electrophoresis, Agar Gel; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D005720:Gamma Rays; D016147:Genes, Tumor Suppressor / Q000235:genetics*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D020287:In Situ Nick-End Labeling; D051379:Mice; D016297:Mutagenesis, Site-Directed; D019913:Nuclear Localization Signals / Q000235:genetics*; D015689:Oncogene Protein p21(ras) / Q000096:biosynthesis; D017384:Sequence Deletion / Q000235:genetics*; D014162:Transfection; D014178:Translocation, Genetic; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
D019913:Nuclear Localization Signals; D016159:Tumor Suppressor Protein p53; D006861:Hydrogen Peroxide; D015689:Oncogene Protein p21(ras)