title: Gene regulation via excitation and BDNF is mediated by induction and phosphorylation of the Etv1 transcription factor in cerebellar granule cells.
abstract: In maturing postnatal cerebellar granule cells, the Etv1/Er81 transcription factor is induced by sequential activity-dependent mechanisms through stimulation of AMPA and NMDA receptors, voltage-dependent Nav1.2 Na(+) channels, and voltage-dependent Ca(2+) channels. Etv1 then up-regulates a battery of maturation genes involved in the cerebellar circuitry. In this process, BDNF is also induced and participates in the up-regulation of these maturation genes. Using cultures of granule cells, we addressed how the activity-dependent and BDNF signaling mechanisms converge on the regulation of the representative NR2C NMDA receptor and Tiam1 maturation genes. BDNF up-regulated both the NR2C and Tiam1 genes via the TrkB-Erk cascade and this up-regulation was blocked not only by inhibition of the activity-dependent signaling mechanisms but also by suppression of Etv1 expression with Etv1 siRNA. Importantly, Etv1 was selectively phosphorylated by Erk1/2 in the BDNF signaling cascade, and the inhibition of this phosphorylation abrogated the BDNF-induced up-regulation of the NR2C and Tiam1 genes. The luciferase reporter assays in combination with mutations of MEK and Etv1 indicated that the Erk-mediated, phosphorylated Etv1 interacted with the Ets motifs of the NR2C promoter sequence and that phosphorylation at both serine 94 and a cluster of threonines and a serine (Thr139, Thr143, and Ser146) of Etv1 was indispensable for the BDNF-mediated activation of the NR2C promoter activity. This study demonstrates that the NR2C and Tiam1 maturation genes are synergistically controlled by the activity-dependent induction of Etv1 and its phosphorylation by the BDNF signaling cascade.
authors.affiliation: Department of Systems Biology,  Osaka Bioscience Institute, Suita, Osaka 565-0874,  Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Abe
authors.forename: Makoto
authors.initials: M
authors.lastname: Okazawa
authors.forename: Shigetada
authors.initials: S
authors.lastname: Nakanishi
mesh_terms: D000818:Animals; D001483:Base Sequence; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism; D015151:Immunoblotting; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D009154:Mutation; D010766:Phosphorylation / Q000187:drug effects; D011401:Promoter Regions, Genetic / Q000235:genetics; D034622:RNA Interference; D020813:Receptor, trkB / Q000235:genetics / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012694:Serine / Q000235:genetics / Q000378:metabolism; D000075684:T-Lymphoma Invasion and Metastasis-inducing Protein 1; D013912:Threonine / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D004268:DNA-Binding Proteins; C490641:Etv1 protein, mouse; D020662:Guanine Nucleotide Exchange Factors; C432823:NR2C NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D000075684:T-Lymphoma Invasion and Metastasis-inducing Protein 1; C513260:Tiam1 protein, mouse; D014157:Transcription Factors; D013912:Threonine; D012694:Serine; D008156:Luciferases; D020813:Receptor, trkB; D048049:Extracellular Signal-Regulated MAP Kinases