The activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 to the distal CCAAT box of the RhoB promoter

• Published in: Biochemical and biophysical research communications 2011-06, Vol.409 (2), p.211-216
• Main Authors: Ahn, Jiwon, Choi, Jeong-Hae, Won, Misun, Kang, Chang-Mo, Gyun, Mi-Rang, Park, Hee-Moon, Kim, Chun-Ho, Chung, Kyung-Sook
• Format: Article
• Language: English
• Subjects: 60 APPLIED LIFE SCIENCES; Activating Transcription Factor 2 - genetics; Activating Transcription Factor 2 - metabolism; APOPTOSIS; Apoptosis - genetics; BIOLOGICAL STRESS; c-Jun; CCAAT box; CCAAT-Binding Factor - metabolism; CELL PROLIFERATION; DISSOCIATION; DNA; E1A-Associated p300 Protein - metabolism; Enzyme Activation; Gene Expression Regulation; GENE REGULATION; Humans; INHIBITION; IRRADIATION; Jurkat Cells; LUCIFERASE; p300; p38 Mitogen-Activated Protein Kinases - antagonists & inhibitors; p38 Mitogen-Activated Protein Kinases - metabolism; Promoter Regions, Genetic; PROMOTERS; Proto-Oncogene Proteins c-jun - genetics; Proto-Oncogene Proteins c-jun - metabolism; RhoB; rhoB GTP-Binding Protein - genetics; TRANSCRIPTION FACTORS; Transcription, Genetic - radiation effects; ULTRAVIOLET RADIATION; Ultraviolet Rays; UV-light
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2011.04.121

► Regulation of transcriptional activation of RhoB is still unclear. ► We examine the effect of p38 MAPK inhibition, and c-Jun and RhoB depletion on UV-induced RhoB expression and apoptosis. ► We identify the regions of RhoB promoter necessary to confer UV responsiveness using pRhoB-luciferase reporter assays. ► c-Jun, ATF2 and p300 are dominantly associated with NF-Y on the distal CCAAT box. ► The activation of p38 MAPK primarily contribute to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins on distal CCAAT box of RhoB promoter. The Ras-related small GTP-binding protein RhoB is rapidly induced in response to genotoxic stresses caused by ionizing radiation. It is known that UV-induced RhoB expression results from the binding of activating transcription factor 2 (ATF2) via NF-Y to the inverted CCAAT box (−23) of the RhoB promoter. Here, we show that the association of c-Jun with the distal CCAAT box (−72) is primarily involved in UV-induced RhoB expression and p38 MAPK regulated RhoB induction through the distal CCAAT box. UV-induced RhoB expression and apoptosis were markedly attenuated by pretreatment with the p38 MAPK inhibitor. siRNA knockdown of RhoB, ATF2 and c-Jun resulted in decreased RhoB expression and eventually restored the growth of UV-irradiated Jurkat cells. In the reporter assay using luciferase under the RhoB promoter, inhibition of RhoB promoter activity by the p38 inhibitor and knockdown of c-Jun using siRNA occurred through the distal CCAAT box. Immunoprecipitation and DNA affinity protein binding assays revealed the association of c-Jun and p300 via NF-YA and the dissociation of histone deacetylase 1 (HDAC1) via c-Jun recruitment to the CCAAT boxes of the RhoB promoter. These results suggest that the activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins to the distal CCAAT box of the RhoB promoter in Jurkat cells.