Referenced in: none

Automatically associated channels: Kv1.4 , Kv1.5

Title: Dexamethasone rapidly induces Kv1.5 K+ channel gene transcription and expression in clonal pituitary cells.

Authors: K Takimoto, A F Fomina, R Gealy, J S Trimmer, E S Levitan

Journal, date & volume: Neuron, 1993 Aug , 11, 359-69

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/8352944

Abstract
Glucocorticoids specifically increase Kv1.5 K+ channel mRNA in normal and clonal (GH3) rat pituitary cells. Here, we demonstrate that dexamethasone, a glucocorticoid agonist, rapidly induces Kv1.5 gene transcription, but does not affect Kv1.5 mRNA turnover (t1/2 approximately 0.5 hr) in GH3 cells. Immunoblots indicate that the steroid also increases the expression of the 76 kd Kv1.5 protein approximately 3-fold within 12 hr without altering its half-life (t1/2 approximately 4 hr). In contrast, Kv1.4 protein expression is unaffected. Finally, we find that the induction of Kv1.5 protein is associated with an increase in a noninactivating component of the voltage-gated K+ current. Our results indicate that hormones and neurotransmitters may act within hours to regulate excitability by controlling K+ channel gene expression.