TY - JOUR
T1 - Phosphoproteomics of the Dopamine Pathway Enables Discovery of Rap1 Activation as a Reward Signal In Vivo
AU - Nagai, Taku
AU - Nakamuta, Shinichi
AU - Kuroda, Keisuke
AU - Nakauchi, Sakura
AU - Nishioka, Tomoki
AU - Takano, Tetsuya
AU - Zhang, Xinjian
AU - Tsuboi, Daisuke
AU - Funahashi, Yasuhiro
AU - Nakano, Takashi
AU - Yoshimoto, Junichiro
AU - Kobayashi, Kenta
AU - Uchigashima, Motokazu
AU - Watanabe, Masahiko
AU - Miura, Masami
AU - Nishi, Akinori
AU - Kobayashi, Kazuto
AU - Yamada, Kiyofumi
AU - Amano, Mutsuki
AU - Kaibuchi, Kozo
N1 - Funding Information:
We thank Drs. Shigetada Nakanishi, Takashi Imai, and Akira Kikuchi for providing the constructs for pAAV-Sp-Cre, pCAGGS-myc-caPKA, and pGEX-2T-RalGDS, respectively. We thank Yasuyuki Kirii and Kohichiro Yoshino for providing GST-PKACA. We are grateful to Takashi Watanabe, Yumi Fukaya, Reon Kondoh, Hiroyuki Takenaka, and other Kaibuchi and Yamada lab members for their skilled assistance; the Division for Research on Laboratory Animals of the Center for Research on Laboratory Animals and Medical Research Engineering for assistance with animal care and use; and the Radioisotope Center Medical Branch for its use. We also thank Akihiro Yamanaka for providing technical assistance for virus purification. We would also like to thank Masasyoshi Mishina, Tsutomu Tanabe, Jeff Wickens, and Joshua Johansen for their excellent advice. This work was supported by the following funding sources: “Bioinformatics for Brain Sciences” and “Integrated Research on Neuropsychiatric Disorders” performed under the SRPBS from MEXT and AMED, Grant-in-Aid for Scientific Research (A) (25251021) from MEXT, Grant-in-Aid for Scientific Research on Innovative Areas (Comprehensive Brain Science Network) from MEXT, and Health and Labour Sciences Research Grant (H25-Iyaku-Ippan-020) from MHLW.
Publisher Copyright:
© 2016 Elsevier Inc.
PY - 2016/2/3
Y1 - 2016/2/3
N2 - 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. Nagai et al. identified more than 100 candidate substrates of PKA downstream of dopamine receptor D1R by a kinase-oriented phosphoproteomic analysis and demonstrated a novel DA-PKA-Rap1-MAPK intracellular signaling mechanism in D1R-MSNs which increases neuronal excitability to enhance reward-related behaviors.
AB - 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. Nagai et al. identified more than 100 candidate substrates of PKA downstream of dopamine receptor D1R by a kinase-oriented phosphoproteomic analysis and demonstrated a novel DA-PKA-Rap1-MAPK intracellular signaling mechanism in D1R-MSNs which increases neuronal excitability to enhance reward-related behaviors.
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U2 - 10.1016/j.neuron.2015.12.019
DO - 10.1016/j.neuron.2015.12.019
M3 - Article
C2 - 26804993
AN - SCOPUS:84958536687
VL - 89
SP - 550
EP - 565
JO - Neuron
JF - Neuron
SN - 0896-6273
IS - 3
ER -