title: GLAST: gene expression regulation by phorbol esters.
abstract: The gene expression regulation of the Na+-dependent high affinity glutamate/aspartate transporter GLAST expressed in cultured Bergmann glia cells from chick cerebellum was studied. A 679 bp fragment of the chick GLAST cDNA was cloned and sequenced. Specific PCR primers were used to quantify chick GLAST mRNA levels. Treatment of the cells with the Ca2+/diacylglycerol dependent protein kinase C (PKC) activator, phorbol 12-tetradecanoyl-13-acetate (TPA) produced a decrease in transporter mRNA levels, without an effect in its mRNA half life, suggesting a transcriptional down regulation. Activation of the cAMP pathway results in a transient decrease in GLAST mRNA levels, in contrast with the TPA effect. These findings suggest that GLAST expression is under control of distinct signaling pathways.
authors.affiliation: Departamento de Genética y Biología Molecular, Cinvestav-IPN, México DF, México.
authors.forename: M
authors.initials: M
authors.lastname: Espinoza-Rojo
authors.forename: E
authors.initials: E
authors.lastname: López-Bayghen
authors.forename: A
authors.initials: A
authors.lastname: Ortega
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000595:Amino Acid Sequence / Q000235:genetics; D027322:Amino Acid Transport System X-AG; D000818:Animals; D001483:Base Sequence / Q000235:genetics; D002531:Cerebellum / Q000196:embryology / Q000378:metabolism; D002642:Chick Embryo; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology; D015870:Gene Expression / Q000187:drug effects*; D008969:Molecular Sequence Data; D011493:Protein Kinase C / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D018528:ATP-Binding Cassette Transporters; D027322:Amino Acid Transport System X-AG; D012333:RNA, Messenger; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate