TY - JOUR
T1 - Arachidonic acid activates a proton current in the rat glutamate transporter EAAT4
AU - Tzingounis, Anastassios V.
AU - Lin, Chien Liang
AU - Rothstein, Jeffrey D.
AU - Kavanaugh, Michael P.
PY - 1998/7/10
Y1 - 1998/7/10
N2 - The excitatory amino acid transporter EAAT4 is expressed predominantly in Purkinje neurons in the rat cerebellum (1-3), and it participates in postsynaptic re-uptake of glutamate released at the climbing fiber synapse (4). Transporter-mediated currents in Purkinje neurons are increased more than 3-fold by arachidonic acid, a second messenger that is liberated following depolarization-induced Ca2+ activation of phospholipase A2 (5). In this study we demonstrate that application of arachidonic acid to oocytes expressing rat EAAT4 increased glutamate-induced currents to a similar extent. However, arachidonic acid did not cause an increase in the rate of glutamate transport or in the chloride current associated with glutamate transport but rather activated a proton-selective conductance. These data reveal a novel action of arachidonate on a glutamate transporter and suggest a mechanism by which synaptic activity may decrease intracellular pH in neurons where this transporter is localized.
AB - The excitatory amino acid transporter EAAT4 is expressed predominantly in Purkinje neurons in the rat cerebellum (1-3), and it participates in postsynaptic re-uptake of glutamate released at the climbing fiber synapse (4). Transporter-mediated currents in Purkinje neurons are increased more than 3-fold by arachidonic acid, a second messenger that is liberated following depolarization-induced Ca2+ activation of phospholipase A2 (5). In this study we demonstrate that application of arachidonic acid to oocytes expressing rat EAAT4 increased glutamate-induced currents to a similar extent. However, arachidonic acid did not cause an increase in the rate of glutamate transport or in the chloride current associated with glutamate transport but rather activated a proton-selective conductance. These data reveal a novel action of arachidonate on a glutamate transporter and suggest a mechanism by which synaptic activity may decrease intracellular pH in neurons where this transporter is localized.
UR - http://www.scopus.com/inward/record.url?scp=0032504238&partnerID=8YFLogxK
U2 - 10.1074/jbc.273.28.17315
DO - 10.1074/jbc.273.28.17315
M3 - Article
C2 - 9651313
AN - SCOPUS:0032504238
SN - 0021-9258
VL - 273
SP - 17315
EP - 17317
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 28
ER -