Control of the Na+/Ca2+ exchanger 3 promoter by cyclic adenosine monophosphate and Ca2+ in differentiating neurons.
The human gene for member 3 of solute carrier family 8 (SLC8A3), encoding the Na+/Ca2+ exchanger isoform 3 (NCX3), was identified on chromosome 14q24.2. The minimal promoter region was predicted 250 bp upstream of exon 1. This was confirmed by luciferase reporter assays of pGL3-promoter constructs in transfected SH-SY5Y cells. The promoter activity was monitored during the differentiation of this cell line elicited by the sequential treatment with retinoic acid and brain-derived neurotrophic factor (BDNF). The activity was induced by cyclic AMP (cAMP) via the CRE (cAMP response element) and was stimulated by retinoic acid. The increase of intracellular Ca2+ induced by the partial depolarization of the plasma membrane with KCl down-regulated both the basal and the cAMP-stimulated transcription. The down-regulation of the latter may be mediated by the phosphorylation of the CRE-binding protein by a calmodulin-dependent kinase (CaMKII). The exposure of cells to BDNF after treatment with retinoic acid rapidly induced promoter activity during the initial five hours and phosphorylation of CRE-binding protein during the first two hours. The promoter activity was further enhanced by cAMP, but became insensitive to Ca2+. In BDNF-stimulated cells cAMP elevation caused the preferential phosphorylation of ATF1 instead of that of CRE-binding protein.
Gabellini
Nadia
N
Department of Biological Chemistry, University of Padova, Italy. nadia.gabellini@unipd.it
Bortoluzzi
Stefania
S
Danieli
Gian A
GA
Carafoli
Ernesto
E
D051696:Activating Transcription Factors; D001483:Base Sequence; D001798:Blood Proteins / Q000378:metabolism; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism* / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D006801:Humans; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D009447:Neuroblastoma / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000502:physiology*; D019831:Sodium-Calcium Exchanger / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects
D051696:Activating Transcription Factors; D001798:Blood Proteins; D019208:Brain-Derived Neurotrophic Factor; D017362:Cyclic AMP Response Element-Binding Protein; D026901:Membrane Transport Proteins; C101832:SLC38A3 protein, human; D019831:Sodium-Calcium Exchanger; D014157:Transcription Factors; D014212:Tretinoin; D000242:Cyclic AMP; D002118:Calcium