Critical role of s465 in protein kinase C-increased rat glutamate transporter type 3 activity.
Glutamate transporters, also called excitatory amino acid transporters (EAATs), uptake extracellular glutamate and regulate neurotransmission. Activation of protein kinase C (PKC) increases the activity of EAAT type 3 (EAAT3), the major neuronal EAAT. We designed this study to determine which amino acid residue(s) in EAAT3 may be involved in this PKC effect. Selective potential PKC phosphorylation sites were mutated. These EAAT3 mutants were expressed in the Xenopus oocytes. Phorbol 12-myristate 13-acetate, a PKC activator, significantly increased wild-type EAAT3 activity. Mutation of serine 465 to alanine or aspartic acid, but not the mutation of threonine 5 to alanine, abolished PKC-increased EAAT3 activity. Our results suggest a critical role of serine 465 in the increased EAAT3 activity by PKC activation.
Baik
Hee Jung
HJ
Department of Anesthesiology, University of Virginia, Charlottesville, VA, USA.
Huang
Yueming
Y
Washington
Jacqueline M
JM
Zuo
Zhiyi
Z
D018685:Anesthetics, Inhalation / Q000494:pharmacology; D000818:Animals; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D003627:Data Interpretation, Statistical; D004594:Electrophysiology; D050580:Excitatory Amino Acid Transporter 3 / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D007530:Isoflurane / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010703:Phorbol Esters / Q000494:pharmacology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000235:genetics* / Q000378:metabolism*; D051381:Rats; D012694:Serine / Q000235:genetics*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014982:Xenopus laevis
D018685:Anesthetics, Inhalation; D018076:DNA, Complementary; D050580:Excitatory Amino Acid Transporter 3; D010703:Phorbol Esters; C493398:Slc1a1 protein, rat; D012694:Serine; D007530:Isoflurane; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate