title: Phosphoproteomics of the Dopamine Pathway Enables Discovery of Rap1 Activation as a Reward Signal In Vivo.
abstract: Dopamine (DA) type 1 receptor (D1R) signaling in the striatum presumably regulates neuronal excitability and reward-related behaviors through PKA. However, whether and how D1Rs and PKA regulate neuronal excitability and behavior remain largely unknown. Here, we developed a phosphoproteomic analysis method to identify known and novel PKA substrates downstream of the D1R and obtained more than 100 candidate substrates, including Rap1 GEF (Rasgrp2). We found that PKA phosphorylation of Rasgrp2 activated its guanine nucleotide-exchange activity on Rap1. Cocaine exposure activated Rap1 in the nucleus accumbens in mice. The expression of constitutively active PKA or Rap1 in accumbal D1R-expressing medium spiny neurons (D1R-MSNs) enhanced neuronal firing rates and behavioral responses to cocaine exposure through MAPK. Knockout of Rap1 in the accumbal D1R-MSNs was sufficient to decrease these phenotypes. These findings demonstrate a novel DA-PKA-Rap1-MAPK intracellular signaling mechanism in D1R-MSNs that increases neuronal excitability to enhance reward-related behaviors.
authors.affiliation: Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Nagai
authors.affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nakamuta
authors.affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kuroda
authors.affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Sakura
authors.initials: S
authors.lastname: Nakauchi
authors.affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Nishioka
authors.affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Takano
authors.affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors.forename: Xinjian
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tsuboi
authors.affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Funahashi
authors.affiliation: Neurobiology Research Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakano
authors.affiliation: Neural Computation Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Junichiro
authors.initials: J
authors.lastname: Yoshimoto
authors.affiliation: Section of Viral Vector Development, National Institute for Physiological Sciences, 38 Nishigonaka Myodaiji, Okazaki 444-8585, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Anatomy, Hokkaido University Graduate School of Medicine, Kita 15, Nishi 7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Motokazu
authors.initials: M
authors.lastname: Uchigashima
authors.affiliation: Department of Anatomy, Hokkaido University Graduate School of Medicine, Kita 15, Nishi 7, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Neuropathophysiology Research Group, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Miura
authors.affiliation: Department of Pharmacology, School of Medicine, Kurume University, 67 Asahi-machi, Kurume 830-0011, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Nishi
authors.affiliation: Department of Molecular Genetics, Institute of Biomedical Sciences, School of Medicine, Fukushima Medical University, 1 Hikariga-oka, Fukushima 960-1295, Japan.
authors.forename: Kazuto
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
authors.forename: Mutsuki
authors.initials: M
authors.lastname: Amano
authors.affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; SRPBS, Japan Agency for Medical Research and Development, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan. Electronic address: kaibuchi@med.nagoya-u.ac.jp.
authors.forename: Kozo
authors.initials: K
authors.lastname: Kaibuchi
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D003042:Cocaine / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism* / Q000494:pharmacology; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism / Q000502:physiology; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009474:Neurons / Q000378:metabolism / Q000502:physiology; D009714:Nucleus Accumbens / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D012201:Reward; D015398:Signal Transduction / Q000187:drug effects; D020827:rap1 GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D001552:Benzazepines; D020662:Guanine Nucleotide Exchange Factors; D010750:Phosphoproteins; D020543:Proteome; C485927:Rasgrp2 protein, mouse; D017447:Receptors, Dopamine D1; D005576:Colforsin; C067113:SK&F 81297; D017868:Cyclic AMP-Dependent Protein Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D020827:rap1 GTP-Binding Proteins; D003042:Cocaine; D004298:Dopamine