Excitatory amino acid-induced AP-1 DNA binding activity in Müller glia.
The effect of L-glutamate (L-Glu) and its structural analogs N-methyl-D-aspartate (NMDA), quisqualate (QA), and kainate (KA) on the DNA binding activity of the Activator Protein 1 (AP-1) and the Ca2+/cAMP Responsive Element Binding Protein (CREB) families of transcription factors was examined in cultured chick retinal Müller glia cells. L-Glu, NMDA, and KA evoked a dose and time dependent increase in AP-1 DNA binding activity and had no effect on CREB binding. The order of potency for stimulating AP-1 DNA binding was NMDA > or = Glu > KA >> QA. L-Glu responses were partially blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and by 3-[RS)-2-carboxypiperazin-4-yl)]-propyl-1-phosphonate (CPP) indicating that the increase in DNA binding is mediated both by an alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA)/low affinity KA and a NMDA subtypes of L-Glu receptors. Since Müller glia L-Glu receptors are probably mediators of the efficacy of the excitatory transmission in the retina, the present findings suggest that a stimulus-transcription coupling triggered by L-Glu in the glial cells might have a role in the long-term modulation of these synapses.
López-Colomé
A M
AM
Instituto de Fisiología Celular-UNAM, Mexico.
Murbartián
J
J
Ortega
A
A
D000818:Animals; D001667:Binding, Competitive; D002478:Cells, Cultured; D002642:Chick Embryo; D004247:DNA / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004586:Electrophoresis; D018846:Excitatory Amino Acids / Q000494:pharmacology*; D018698:Glutamic Acid / Q000494:pharmacology; D016202:N-Methylaspartate / Q000494:pharmacology; D009457:Neuroglia / Q000378:metabolism*; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000378:metabolism
D018846:Excitatory Amino Acids; D018808:Transcription Factor AP-1; D018698:Glutamic Acid; D016202:N-Methylaspartate; D004247:DNA