A conserved methionine residue controls the substrate selectivity of a neuronal glutamate transporter.

ABSTRACT: Glutamate transporters located in the brain maintain low synaptic concentrations of the neurotransmitter by coupling its flux to that of sodium and other cations. In the binding pocket of the archeal homologue Glt(Ph), a conserved methionine residue has been implicated in the binding of the benzyl moiety of the nontransportable substrate analogue threo-beta-benzyloxyaspartate. To determine whether the corresponding methionine residue of the neuronal glutamate transporter EAAC1, Met-367, fulfills a similar role, M367L, M367C, and M367S mutants were expressed in HeLa cells and Xenopus laevis oocytes to monitor radioactive transport and transport currents, respectively. The apparent affinity of the Met-367 mutants for D-aspartate and L-glutamate, but not for L-aspartate, was 10-20-fold reduce

SUBMITTER: Rosental N 

PROVIDER: S-EPMC2898430 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature