p14ARF is a component of the p53 response following ionizing irradiation of normal human fibroblasts.
Ionizing radiation leads to rapid stabilization and activation of the p53 tumor suppressor. Previous reports demonstrate that murine p19ARF cooperates with p53 in the cellular response to gamma irradiation. Here, we show that endogenous ARF sequentially interacts with p53 and MDM2 following irradiation of primary human and mouse embryonic fibroblasts. Shortly after irradiation, p14ARF binds p53 independently of MDM2. As nuclear pools of p53 decline, endogenous p14ARF co-immunoprecipitates with MDM2 and is localized within the nucleolus. Interestingly, p14ARF nucleolar localization during this response is abrogated in cells lacking functional p53. Taken together, our data suggest that human and murine ARF contribute to the mammalian DNA damage response.
Khan
Shireen
S
Department of Discovery Research, DNAX Research Incorporated, Palo Alto, CA 94304, USA.
Guevara
Claudia
C
Fujii
Greg
G
Parry
David
D
D000818:Animals; D002460:Cell Line; D002466:Cell Nucleolus / Q000737:chemistry; D019941:Cyclin-Dependent Kinase Inhibitor p16; D004249:DNA Damage; D005347:Fibroblasts / Q000378:metabolism / Q000528:radiation effects; D006801:Humans; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051736:Proto-Oncogene Proteins c-mdm2; D011839:Radiation, Ionizing; D025803:Tumor Suppressor Protein p14ARF / Q000032:analysis / Q000378:metabolism / Q000502:physiology*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis / Q000378:metabolism*
C417743:Cdkn2a protein, mouse; D019941:Cyclin-Dependent Kinase Inhibitor p16; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D025803:Tumor Suppressor Protein p14ARF; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; C497207:Mdm2 protein, mouse; D051736:Proto-Oncogene Proteins c-mdm2