title: Differential expression of two-pore domain potassium channels in rat cerebellar granule neurons.
abstract: Two pore domain potassium (K2P) channels are mostly present in the central nervous system (CNS) where they play important roles in modulating neuronal excitability. K2P channels give rise to background K(+) currents (IKSO) a key component in setting and maintaining the resting membrane potential in excitable cells. Here, we studied the expression and relative abundances of K2P channels in cerebellar granule neurons (CGNs), combining molecular biology, electrophysiology and immunologic techniques. The CGN IKSO was very sensitive to external pH, as previously reported. Quantitative determination of mRNA expression level demonstrated the existence of an accumulation pattern of transcripts in CGN that encode K2P9>K2P1>K2P3>K2P18>K2P2=K2P10>K2P4>K2P5 subunits. The presence of the major K2P subunits expressed was then confirmed by Western blot and immunofluorescence analysis, demonstrating robust expression of K2P1 (TWIK-1), K2P3 (TASK-1), K2P9 (TASK-3) and K2P18 (TRESK) channel protein. Based, on these results, it is concluded that K2P1, -3, -9 and -18 subunits represent the majority component of IKSO current in CGN.
authors.affiliation: Centro de Investigaciones Médicas CIM, Escuela de Medicina, Universidad de Talca, Talca, Chile.
authors.forename: Paulina
authors.initials: P
authors.lastname: Burgos
authors.affiliation: Centro de Investigaciones Médicas CIM, Escuela de Medicina, Universidad de Talca, Talca, Chile.
authors.forename: Rafael
authors.initials: R
authors.lastname: Zúñiga
authors.affiliation: Centro de Investigaciones Médicas CIM, Escuela de Medicina, Universidad de Talca, Talca, Chile.
authors.forename: Pedro
authors.initials: P
authors.lastname: Domínguez
authors.affiliation: Facultad de Medicina, Universidad Católica del Maule, Talca, Chile.
authors.forename: Fernando
authors.initials: F
authors.lastname: Delgado-López
authors.affiliation: Department of Biochemistry, Brandeis University, Waltham, USA.
authors.forename: Leigh D
authors.initials: LD
authors.lastname: Plant
authors.affiliation: Centro de Investigaciones Médicas CIM, Escuela de Medicina, Universidad de Talca, Talca, Chile. Electronic address: lzuniga@utalca.cl.
authors.forename: Leandro
authors.initials: L
authors.lastname: Zúñiga
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D015640:Ion Channel Gating / Q000502:physiology; D009474:Neurons / Q000378:metabolism*; D016062:Porosity; D015221:Potassium Channels / Q000737:chemistry* / Q000145:classification / Q000378:metabolism*; D024683:Potassium Channels, Tandem Pore Domain / Q000737:chemistry* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D015221:Potassium Channels; D024683:Potassium Channels, Tandem Pore Domain
keywords: Cerebellar granule neurons (CGNs); K2P channels; Two-pore domain potassium channels