title: Deletion of the kinase domain from death-associated protein kinase attenuates p53 expression in chronic obstructive uropathy.
abstract: Death-associated protein kinase (DAPK) is a Ca(2+)/calmodulin-dependent serine/threonine kinase that is thought to mediate apoptosis. We previously showed that the kinase domain of DAPK is crucial for the induction of renal tubular cell apoptosis in chronic obstructive uropathy (COU) caused by a unilateral ureteral ligation. Here, we used DAPK-mutant mice, generated by the deletion of 74 amino acids from the catalytic kinase domain, to investigate the role of the DAPK kinase domain in regulating the p53 level following COU. The p53 expression levels in obstructed kidneys of wild-type and mutant mice were determined during the course of COU. Western blot analysis revealed that the p53 protein levels were significantly increased at 5 days after a ureteral ligation. This increase in the p53 level was significantly attenuated in mutant kidneys compared to wild-type kidneys. The obstructed kidneys of DAPK-mutant mice showed a significantly lower number of p53-expressing renal tubule cells than wild-type mice. These results are consistent with the hypothesis that DAPK stabilizes p53 protein in response to apoptosis-inducing stimuli. Thus, the present results suggest that the DAPK kinase domain is crucial for stabilizing p53 protein in renal tubular cell apoptosis in a mouse model of COU.
authors.affiliation: Department of Physiology, Wakayama Medical University, Japan. kazu59@wakayama-med.ac.jp
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yukawa
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Hoshino
authors.forename: Masanori
authors.initials: M
authors.lastname: Kishino
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tsubota
authors.forename: Kyoko
authors.initials: K
authors.lastname: Owada-Makabe
authors.forename: Masanobu
authors.initials: M
authors.lastname: Maeda
authors.forename: Tao
authors.initials: T
authors.lastname: Bai
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Tanaka
authors.forename: Shizuo
authors.initials: S
authors.lastname: Akira
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins; D015153:Blotting, Western; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics* / Q000378:metabolism; D020134:Catalytic Domain / Q000235:genetics*; D002908:Chronic Disease; D064550:Death-Associated Protein Kinases; D017353:Gene Deletion; D005838:Genotype; D007150:Immunohistochemistry; D007684:Kidney Tubules / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009154:Mutation; D010770:Phosphotransferases / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*; D014517:Ureteral Obstruction / Q000235:genetics / Q000378:metabolism*
chemical_list: D051017:Apoptosis Regulatory Proteins; D016159:Tumor Suppressor Protein p53; D010770:Phosphotransferases; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases