title: Circadian regulation of a transcription factor, ApC/EBP, in the eye of Aplysia californica.
abstract: The transcription factor, ApC/EBP (Aplysia CCAAT enhancer-binding protein) is an immediate early gene that is rapidly induced by serotonin and the cAMP signaling pathway. ApC/EBP acts as an important link following the activation of protein kinase A (PKA) in the consolidation of long-term memory in Aplysia californica. In this study, we report that levels of ApC/EBP mRNA in the eye of Aplysia are modulated by serotonin or light. These responses of ApC/EBP to serotonin and light are mimicked by analogs of cAMP and cGMP. Expression of ApC/EBP in the eye is also under the control of the circadian oscillator with circadian rhythms of ApC/EBP mRNA present under constant dark conditions. Therefore, ApC/EBP is a candidate gene for a circadian transcription factor to mediate circadian responses activated by the cAMP and cGMP second messenger signaling pathways.
authors.affiliation: Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204-5001, USA.
authors.forename: Samer
authors.initials: S
authors.lastname: Hattar
authors.forename: Lisa C
authors.initials: LC
authors.lastname: Lyons
authors.forename: Arnold
authors.initials: A
authors.lastname: Eskin
mesh_terms: D000367:Age Factors; D000818:Animals; D001048:Aplysia; D001683:Biological Clocks; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D003624:Darkness; D005123:Eye / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D017781:Genes, Immediate-Early / Q000502:physiology; D066298:In Vitro Techniques; D008027:Light; D012333:RNA, Messenger / Q000378:metabolism; D015290:Second Messenger Systems / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D012701:Serotonin; D000242:Cyclic AMP; D006152:Cyclic GMP