5-Hydroxytryptamine2A receptor stimulation induces activator protein-1 and cyclic AMP-responsive element binding with cyclic AMP-responsive element-binding protein and Jun D as common components in cerebellar neurons.
Previous studies from our laboratory have demonstrated that stimulation of 5-hydroxytryptamine2A receptors in rat cerebellar granule cells produces an increase in the levels of 5-hydroxytryptamine2A receptor messenger RNA and binding sites, and that this up-regulation requires de novo RNA and protein synthesis. Here we showed that up-regulation of 5-hydroxytryptamine2A receptor binding sites induced by stimulation with the 5-hydroxytryptamine2A/2C receptor agonist, (+/-)-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), is associated with an increase in the 5-hydroxytryptamine2A receptor transcription rate. To examine the possible role of transcriptional activation in DOI-induced 5-hydroxytryptamine2A receptor up-regulation, we studied the effects of DOI on transcription factor binding to activator protein-1 and cyclic AMP-responsive element (CRE) DNA consensus sequences. We found that DOI induces a time-dependent increase in activator protein-1 and CRE transcription factor binding activity, which is blocked by 5-hydroxytryptamine2A receptor antagonists. Similar to 5-hydroxytryptamine2A receptor up-regulation, DOI-induced activator protein-1 binding is suppressed by inhibitors of calmodulin and Ca2+/calmodulin-dependent kinases. The increased activator protein-1 binding is effectively competed by excessive activator protein-1 and CRE sequences as well as endogenous activator protein-1-like sequences present in the rat 5-hydroxytryptamine2A receptor gene. Supershift assays revealed that cAMP-responsive element-binding protein (CREB) and Jun D are common components of both activator protein-1 and CRE binding complexes. DOI also increased the level of phospho-CREB in a time-dependent manner. The binding of phospho-CREB transcription factor to the activator protein-1 site suggests that CREB may modulate the transcription of genes that contain activator protein-1 but lack CRE site in their promoters, through interaction with the activator protein-1 site. The rat 5-hydroxytryptamine2A receptor up-regulation may involve such a mechanism.
Chalecka-Franaszek
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Section on Molecular Neurobiology, Biological Psychiatry Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
Chen
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Chuang
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D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000031:analogs & derivatives / Q000494:pharmacology; D000662:Amphetamines / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D002478:Cells, Cultured; D002531:Cerebellum / Q000502:physiology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D007093:Imidazoles / Q000494:pharmacology; D007700:Kinetics; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000235:genetics*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects; D015854:Up-Regulation
D000662:Amphetamines; D017362:Cyclic AMP Response Element-Binding Protein; D004791:Enzyme Inhibitors; D007093:Imidazoles; D016755:Proto-Oncogene Proteins c-jun; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; D017366:Serotonin Receptor Agonists; D018808:Transcription Factor AP-1; C031938:calmidazolium; C063302:KN 62; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine