title: Regulation of dendritic development by BDNF requires activation of CRTC1 by glutamate.
abstract: Dendritic growth is essential for the establishment of a functional nervous system. Among extrinsic signals that control dendritic development, substantial evidence indicates that BDNF regulates dendritic morphology. However, little is known about the underlying mechanisms by which BDNF controls dendritic growth. In this study, we show that the MAPK signaling pathway and the transcription factor cAMP response element-binding protein (CREB) mediate the effects of BDNF on dendritic length and complexity. However, phosphorylation of CREB alone is not sufficient for the stimulation of dendritic growth by BDNF. Thus, using a mutant form of CREB unable to bind CREB-regulated transcription coactivator (CRTC1), we demonstrate that this effect also requires a functional interaction between CREB and CRTC1. Moreover, inhibition of CRTC1 expression by shRNA-mediated knockdown abolished BDNF-induced dendritic growth of cortical neurons. Interestingly, we found that nuclear translocation of CRTC1 results from activation of NMDA receptors by glutamate, a process that is essential for the effects of BDNF on dendritic development. Together, these data identify a previously unrecognized mechanism by which CREB and the coactivator CRTC1 mediate the effects of BDNF on dendritic growth.
authors.affiliation: Department of Physiology, University of Lausanne, CH-1005 Lausanne, Switzerland.
authors.forename: Charles
authors.initials: C
authors.lastname: Finsterwald
authors.forename: Hubert
authors.initials: H
authors.lastname: Fiumelli
authors.forename: Jean-René
authors.initials: JR
authors.lastname: Cardinaux
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Martin
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects / Q000502:physiology; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism*; D003712:Dendrites / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D018698:Glutamic Acid / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D009154:Mutation; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C519510:Crtc1 protein, rat; D017362:Cyclic AMP Response Element-Binding Protein; D014157:Transcription Factors; D018698:Glutamic Acid