title: Haloperidol regulates the phosphorylation level of the MEK-ERK-p90RSK signal pathway via protein phosphatase 2A in the rat frontal cortex.
abstract: Haloperidol, a classical antipsychotic drug, affects the extracellular signal-regulated kinase (ERK) pathway in the brain. However, findings are inconsistent and the mechanism by which haloperidol regulates ERK is poorly understood. Therefore, we examined the ERK pathway and the related protein phosphatase 2A (PP2A) in detail after haloperidol administration. Haloperidol (0.5 and 1 mg/kg) induced biphasic changes in the phosphorylation level of mitogen-activated protein kinase kinase (MEK), ERK, and p90 ribosomal S6 kinase (p90RSK) without changing Raf-1 phosphorylation. Fifteen minutes after haloperidol administration, MEK-ERK-p90RSK phosphorylation increased, whilst PP2A activity decreased. At 60 min, the reverse was observed and the binding of PP2A to MEK and ERK increased. Higher dosages of haloperidol (2 and 4 mg/kg), affected neither MEK-ERK-p90RSK phosphorylation nor PP2A activity. Accordingly, PP2A regulates acute dose- and time-dependent changes in MEK-ERK-p90RSK phosphorylation after haloperidol treatment. These findings suggest the involvement of a dephosphorylating mechanism in the acute action of haloperidol.
authors.affiliation: Department of Psychiatry and Behavioral Science, Seoul National University College of Medicine, and Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Se Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Myoung Suk
authors.initials: MS
authors.lastname: Seo
authors.forename: Won Je
authors.initials: WJ
authors.lastname: Jeon
authors.forename: Hyun-Sook
authors.initials: HS
authors.lastname: Yu
authors.forename: Hong Geun
authors.initials: HG
authors.lastname: Park
authors.forename: Gyung-Ah
authors.initials: GA
authors.lastname: Jung
authors.forename: Hee Young
authors.initials: HY
authors.lastname: Lee
authors.forename: Ung Gu
authors.initials: UG
authors.lastname: Kang
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Kim
mesh_terms: D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology*; D015153:Blotting, Western; D004305:Dose-Response Relationship, Drug; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000502:physiology*; D006220:Haloperidol / Q000494:pharmacology*; D047468:Immunoprecipitation; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000502:physiology*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D017397:Prefrontal Cortex / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D054648:Protein Phosphatase 2 / Q000502:physiology*; D019908:Proto-Oncogene Proteins c-raf / Q000235:genetics / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects*; D048490:raf Kinases / Q000502:physiology
chemical_list: D014150:Antipsychotic Agents; D019908:Proto-Oncogene Proteins c-raf; D038744:Ribosomal Protein S6 Kinases, 90-kDa; D048490:raf Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D020928:Mitogen-Activated Protein Kinases; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; D006220:Haloperidol