Observatorio de I+D+i UPM

Memorias de investigación
Research Publications in journals:
The pH-sensor of the plant K+ uptake channel KAT1 is built of a sensory cloud rather than of single key amino acids.
Year:2012
Research Areas
  • Plants and animal biology and ecology
Information
Abstract
The uptake of potassium ions (K+) accompanied by an acidification of the apoplasm is a prerequisite for stomatal opening. The acidification (approximately 2-2.5 pH units) is perceived by voltage-gated inward potassium channels (K(in)) that then can open their pores with lower energy cost. The sensory units for extracellular pH in stomatal K(in) channels are proposed to be histidines exposed to the apoplasm. However, in the Arabidopsis thaliana stomatal K(in) channel KAT1, mutations in the unique histidine exposed to the solvent (His267) do not affect the pH dependency. We demonstrate in the present study that His267 of the KAT1 channel cannot sense pH changes since the neighbouring residue Phe266 shifts its pKa to undetectable values through a cation-? interaction. Instead, we show that Glu240 placed in the extracellular loop between transmembrane segments S5 and S6 is involved in the extracellular acid activation mechanism. Based on structural models we propose that this region may serve as a molecular link between the pH- and the voltage-sensor. Like Glu240, several other titratable residues could contribute to the pH-sensor of KAT1, interact with each other and even connect such residues far away from the voltage-sensor with the gating machinery of the channel.
International
Si
JCR
Si
Title
Biochemical Journal
ISBN
0264-6021
Impact factor JCR
5,016
Impact info
Datos JCR del año 2010 time cited: 1 (05.12.2012)
Volume
442
Journal number
From page
57
To page
63
Month
FEBRERO
Ranking
61/290 BIOCHEMISTRY & MOLECULAR BIOLOGY (SCI)
Participants
  • Autor: Wendy González (Universidad de Talca, Chile)
  • Autor: Janin Riedelsberger (Universität Potsdam, Germany)
  • Autor: Samuel E. Morales-Navarro (Universidad de Talca, Chile)
  • Autor: Julio Caballero (Universidad de Talca, Chile)
  • Autor: Jans H. Alzate-Morales (Universidad de Talca, Chile)
  • Autor: Fernando D. González-Nilo (Universidad de Talca, Chile)
  • Autor: Ingo Dreyer . (UPM)
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Redes Reguladoras del Desarrollo y Respuesta a Estrés en Plantas
  • Centro o Instituto I+D+i: Centro de Biotecnología y Genómica de Plantas, CBGP
  • Departamento: Biotecnología
S2i 2020 Observatorio de investigación @ UPM con la colaboración del Consejo Social UPM
Cofinanciación del MINECO en el marco del Programa INNCIDE 2011 (OTR-2011-0236)
Cofinanciación del MINECO en el marco del Programa INNPACTO (IPT-020000-2010-22)