cAMP-responding element-binding protein and c-Ets1 interact in the regulation of ATP-dependent MUC5AC gene expression.
Exogenous ATP activates purinoreceptors on the cell surface that regulate diverse cellular functions, including mucous cell secretion in the respiratory epithelium. In this study, ATP increased MUC5AC mRNA in primary human nasal epithelial cells and in NCI-H292 pulmonary adenocarcinoma cells in vitro. ATP-induced MUC5AC mRNA was mediated by phospholipase Cbeta3. A dominant-negative mutation in the PDZ binding domain of PLCbeta3 inhibited ATP-induced MUC5AC gene expression. ATP sequentially activated the phosphorylation of Akt, ERK1/2, p38, RSK1, and cAMP-responding element-binding protein (CREB) in a protein kinase C-independent manner. ATP-induced MUC5AC mRNA levels were regulated by CREB via direct interaction with c-Ets1 on the MUC5AC gene promoter (located -938 to -930). Effects of CREB and c-Ets1 were additive. Inhibition of either CREB or c-Ets1 inhibited ATP-induced MUC5AC gene expression. Stimulation with ATP caused the direct binding of CREB and c-Ets1 to the MUC5AC promoter, increasing the phosphorylation of c-Ets1. Chromatin immunoprecipitation assays demonstrated that in the presence of ATP, both c-Ets1 and CREB bound to the MUC5AC promoter. The effects of exogenous ATP on MUC5AC gene expression are mediated by a complex regulatory cascade controlling interactions between CREB and c-Ets1 that bind to a promoter element in the MUC5AC gene enhancing MUC5AC gene transcription. ATP-dependent activation of MUC5AC gene expression via CREB-c-Ets1 may contribute to mucous cell hypersecretion associated with common respiratory disorders.
Song
Kyoung Seob
KS
Airway Mucus Institute, Yonsei University College of Medicine, 134 Shinchon-Dong, Seodaemun-gu, Seoul 120-752, Korea.
Lee
Tae-Jin
TJ
Kim
Kyubo
K
Chung
Kwang Chul
KC
Yoon
Joo-Heon
JH
D000255:Adenosine Triphosphate / Q000378:metabolism; D050882:CREB-Binding Protein / Q000378:metabolism*; D045744:Cell Line, Tumor; D000242:Cyclic AMP / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D055271:Mucin 5AC; D009077:Mucins / Q000096:biosynthesis*; D009297:Nasal Mucosa / Q000378:metabolism* / Q000473:pathology; D054799:Phospholipase C beta / Q000378:metabolism; D050784:Proto-Oncogene Protein c-ets-1 / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012140:Respiratory Tract Diseases / Q000378:metabolism / Q000473:pathology; D020218:Response Elements; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism; D014158:Transcription, Genetic; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
C524678:MUC5AC protein, human; D055271:Mucin 5AC; D009077:Mucins; D050784:Proto-Oncogene Protein c-ets-1; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D050882:CREB-Binding Protein; C494363:CREBBP protein, human; D051057:Proto-Oncogene Proteins c-akt; C069329:RPS6KA1 protein, human; D038744:Ribosomal Protein S6 Kinases, 90-kDa; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; C518039:PLCB3 protein, human; D054799:Phospholipase C beta