Functional role of NF-IL6beta and its sumoylation and acetylation modifications in promoter activation of cyclooxygenase 2 gene.
NF-IL6beta regulates gene expression and plays function roles in many tissues. The EGF-regulated cyclooxygenase-2 (cox-2) expression is mediated through p38(MAPK) signaling pathway and positively correlates with NF-IL6beta expression in A431 cells. NF-IL6beta coordinated with c-Jun on cox-2 transcriptional activation by reporter and small interfering RNA assays. NF-IL6beta could directly bind to CCAAT/enhancer-binding protein (C/EBP) and cyclic AMP-response element (CRE) sites of the cox-2 promoter by in vitro-DNA binding assay. The C/EBP site was important for basal and, to a lesser extent, for EGF-regulated cox-2 transcription, while the CRE site was a more specific response to EGF inducibility of cox-2 gene. SUMO1 expression attenuated EGF- and NF-IL6beta-induced cox-2 promoter activities. NF-IL6beta was found to be sumoylated by in vivo- and in vitro-sumoylation assays, and the SUMO1-NF-IL6beta (suNF-IL6beta) lost its ability to interact with p300 in in vitro-binding assay. NF-IL6beta was also acetylated by p300, and acetylation of NF-IL6beta enhanced the cox-2 promoter activity stimulated by NF-IL6beta itself. In vivo-DNA binding assay demonstrated that EGF stimulated the recruitment of p300 and NF-IL6beta to the cox-2 promoter, yet promoted the dissociation of SUMO1-modificated proteins from the promoter. These results indicated that NF-IL6beta plays a pivotal role in the regulation of basal and EGF-induced cox-2 transcription.
Wang
Ju-Ming
JM
Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Ko
Chiung-Yuan
CY
Chen
Lei-Chin
LC
Wang
Wen-Lin
WL
Chang
Wen-Chang
WC
D000107:Acetylation; D000818:Animals; D001665:Binding Sites; D051743:CCAAT-Enhancer-Binding Protein-delta / Q000378:metabolism* / Q000502:physiology; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D045744:Cell Line, Tumor; D000242:Cyclic AMP / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000096:biosynthesis / Q000235:genetics*; D004815:Epidermal Growth Factor / Q000037:antagonists & inhibitors; D015971:Gene Expression Regulation, Enzymologic; D051548:Histone Acetyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011499:Protein Processing, Post-Translational; D011725:Pyridines / Q000494:pharmacology; D020218:Response Elements; D025842:SUMO-1 Protein / Q000378:metabolism; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000378:metabolism; D015533:Transcriptional Activation; D050880:p300-CBP Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D000099224:p300-CBP-Associated Factor
D051743:CCAAT-Enhancer-Binding Protein-delta; D022762:CCAAT-Enhancer-Binding Proteins; D018797:Cell Cycle Proteins; D000242:Cyclic AMP; D051546:Cyclooxygenase 2; D004815:Epidermal Growth Factor; D051548:Histone Acetyltransferases; D007093:Imidazoles; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D025842:SUMO-1 Protein; D014157:Transcription Factors; D050880:p300-CBP Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases; D000099224:p300-CBP-Associated Factor; C497252:CEBPD protein, human; C093642:SB 203580