title: Activity-dependent transcriptional activation and mRNA stabilization for cumulative expression of pituitary adenylate cyclase-activating polypeptide mRNA controlled by calcium and cAMP signals in neurons.
abstract: Although it has been established that an activity-dependent gene transcription is induced by the calcium (Ca(2+)) signals in neurons, it is unclear how the specific mRNA moieties are transiently accumulated in response to synaptic transmission which evokes multiple intracellular signals including Ca(2+) and cAMP ones. The expression of pituitary adenylate cyclase activating polypeptide (PACAP), a neuropeptide, is controlled by Ca(2+) signals evoked via membrane depolarization in neurons, and, in cultured rat cortical neuronal cells, we found that the Ca(2+) signal-mediated activation of the PACAP gene promoter was critically controlled by a single cAMP-response element (CRE) located at around -200, to which the CRE-binding protein predominantly bound. The Ca(2+) signal-induced expression of PACAP mRNA was enhanced by forskolin, which evokes cAMP signals. In support, the PACAP gene promoter was synergistically enhanced by Ca(2+) and cAMP signals through the CRE, accompanying a prolonged activation of extracellular signal-related protein kinase 1/2 and CRE-binding protein. On the other hand, sole administration of forskolin markedly reduced the cellular content of PACAP mRNA, which was restored by the addition of Ca(2+) signals. We found that the stability of PACAP mRNA was increased in response to Ca(2+) signals but not that of activity-regulated cytoskeleton-associated protein (Arc) mRNA, indicating an activity-dependent stabilization of specific mRNA species in neurons, which can antagonize the regulation mediated by cAMP signals. Thus, the transcriptional activation and mRNA stabilization are coordinately regulated by Ca(2+) and cAMP signals for the cumulative expression of PACAP mRNA in neurons.
authors.affiliation: Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Sugitani 2630, Toyama 931-0194, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Fukuchi
authors.forename: Akiko
authors.initials: A
authors.lastname: Tabuchi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tsuda
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D005576:Colforsin / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism*; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism; D004622:Embryo, Mammalian / Q000502:physiology; D004789:Enzyme Activation; D005091:Exons; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D017930:Genes, Reporter; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011401:Promoter Regions, Genetic; D020871:RNA Stability; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015533:Transcriptional Activation
chemical_list: C495403:Adcyap1 protein, rat; D017362:Cyclic AMP Response Element-Binding Protein; D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D012333:RNA, Messenger; D005576:Colforsin; D000242:Cyclic AMP; D048049:Extracellular Signal-Regulated MAP Kinases; D002118:Calcium