The c-Abl tyrosine kinase stabilizes Pitx1 in the apoptotic response to DNA damage.
In the DNA damage response, c-Abl tyrosine kinase is transiently accumulated in the nucleus and induces apoptosis; however, little is known about the mechanism underlying apoptosis induction via nuclear c-Abl. Here we demonstrate that the expression of human pituitary homeobox 1 (Pitx1) transcription factor is increased after DNA damage. Notably, c-Abl controls augmentation of Pitx1 at the post-transcriptional level. Overexpression of c-Abl induces tyrosine phosphorylation of Pitx1, either directly or indirectly. We also show that, upon exposure to genotoxic stress, overexpression of Pitx1 is associated with marked induction of apoptosis that is independent of p53 status. Importantly, inhibition of c-Abl kinase activity substantially attenuates Pitx1-mediated apoptosis. These findings provide evidence that c-Abl participates in modulating Pitx1 expression in the apoptotic response to DNA damage.
Yamaguchi
Tomoko
T
Department of Molecular Genetics, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku, Japan.
Miki
Yoshio
Y
Yoshida
Kiyotsugu
K
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002460:Cell Line; D004249:DNA Damage; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D051761:Paired Box Transcription Factors / Q000235:genetics / Q000378:metabolism*; D016315:Proto-Oncogene Proteins c-abl / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism
D051761:Paired Box Transcription Factors; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; D016159:Tumor Suppressor Protein p53; D025801:Ubiquitin; C101485:homeobox protein PITX1; D016315:Proto-Oncogene Proteins c-abl