title: Control of alternative splicing of potassium channels by stress hormones.
abstract: Many molecular mechanisms for neural adaptation to stress remain unknown. Expression of alternative splice variants of Slo, a gene encoding calcium- and voltage-activated potassium channels, was measured in rat adrenal chromaffin tissue from normal and hypophysectomized animals. Hypophysectomy triggered an abrupt decrease in the proportion of Slo transcripts containing a "STREX" exon. The decrease was prevented by adrenocorticotropic hormone injections. In Xenopus oocytes, STREX variants produced channels with functional properties associated with enhanced repetitive firing. Thus, the hormonal stress axis is likely to control the excitable properties of epinephrine-secreting cells by regulating alternative splicing of Slo messenger RNA.
authors.affiliation: Section of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA.
authors.forename: J
authors.initials: J
authors.lastname: Xie
authors.forename: D P
authors.initials: DP
authors.lastname: McCobb
mesh_terms: D000313:Adrenal Medulla / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000378:metabolism / Q000494:pharmacology*; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D019439:Chromaffin Cells / Q000378:metabolism*; D003345:Corticosterone / Q000097:blood / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology; D004837:Epinephrine / Q000378:metabolism; D005091:Exons; D005260:Female; D007016:Hypophysectomy; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D051036:Large-Conductance Calcium-Activated Potassium Channels; D008297:Male; D008969:Molecular Sequence Data; D009865:Oocytes; D010625:Phenylethanolamine N-Methyltransferase / Q000235:genetics; D016133:Polymerase Chain Reaction; D015221:Potassium Channels / Q000235:genetics*; D024681:Potassium Channels, Calcium-Activated; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014981:Xenopus
chemical_list: C494842:Kcnma1 protein, rat; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D051036:Large-Conductance Calcium-Activated Potassium Channels; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated; D012333:RNA, Messenger; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D010625:Phenylethanolamine N-Methyltransferase; D003345:Corticosterone; D004837:Epinephrine