title: Characterization of the human alpha1 beta1 soluble guanylyl cyclase promoter: key role for NF-kappaB(p50) and CCAAT-binding factors in regulating expression of the nitric oxide receptor.
abstract: Soluble guanylyl cyclase (sGC) is the principal receptor for NO and plays a ubiquitous role in regulating cellular function. This is exemplified in the cardiovascular system where sGC governs smooth muscle tone and growth, vascular permeability, leukocyte flux, and platelet aggregation. As a consequence, aberrant NO-sGC signaling has been linked to diseases including hypertension, atherosclerosis, and stroke. Despite these key (patho)physiological roles, little is known about the expressional regulation of sGC. To address this deficit, we have characterized the promoter activity of human alpha(1) and beta(1) sGC genes in a cell type relevant to cardiovascular (patho)physiology, primary human aortic smooth muscle cells. Luciferase reporter constructs revealed that the 0.3- and 0.5-kb regions upstream of the transcription start sites were optimal for alpha(1) and beta(1) sGC promoter activity, respectively. Deletion of consensus sites for c-Myb, GAGA, NFAT, NF-kappaB(p50), and CCAAT-binding factor(s) (CCAAT-BF) revealed that these are the principal transcription factors regulating basal sGC expression. In addition, under pro-inflammatory conditions, the effects of the strongest alpha(1) and beta(1) sGC repressors were enhanced, and enzyme expression and activity were reduced; in particular, NF-kappaB(p50) is pivotal in regulating enzyme expression under such conditions. NO itself also elicited a cGMP-independent negative feedback effect on sGC promoter activity that is mediated, in part, via CCAAT-BF activity. In sum, these data provide a systematic characterization of the promoter activity of human sGC alpha(1) and beta(1) subunits and identify key transcription factors that govern subunit expression under basal and pro-inflammatory (i.e. atherogenic) conditions and in the presence of ligand NO.
authors.affiliation: Department of Pharmacology, University College London, Medical Sciences Building, London, UK.
authors.forename: Martín L
authors.initials: ML
authors.lastname: Marro
authors.forename: Concepción
authors.initials: C
authors.lastname: Peiró
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Panayiotou
authors.forename: Reshma S
authors.initials: RS
authors.lastname: Baliga
authors.forename: Sabine
authors.initials: S
authors.lastname: Meurer
authors.forename: Harald H H W
authors.initials: HH
authors.lastname: Schmidt
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Hobbs
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D001665:Binding Sites; D023081:CCAAT-Binding Factor / Q000378:metabolism*; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D052002:NF-kappa B p50 Subunit / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics*; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D000071756:Soluble Guanylyl Cyclase; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D023081:CCAAT-Binding Factor; D004791:Enzyme Inhibitors; D052002:NF-kappa B p50 Subunit; D018160:Receptors, Cytoplasmic and Nuclear; D009569:Nitric Oxide; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase