RT Journal Article
SR Electronic
T1 Extracellular Signal-Regulated Kinase 1/2-Mediated Transcriptional Regulation of G-Protein-Coupled Receptor Kinase 3 Expression in Neuronal Cells
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 51
OP 59
DO 10.1124/jpet.106.116921
VO 321
IS 1
A1 Samina Salim
A1 Kelly M. Standifer
A1 Douglas C. Eikenburg
YR 2007
UL http://jpet.aspetjournals.org/content/321/1/51.abstract
AB Relatively small changes in G-protein-coupled receptor kinase (GRK) 3 expression (∼2-fold) profoundly affect α2-adrenergic receptor (AR) function and preferentially regulate neuronal α2A- and α2B-AR signaling. In the present study, we provide evidence that epinephrine (EPI)-induced up-regulation of GRK3 protein expression in two neuronal cell lines, BE(2)-C cells (endogenously express α2A- and β2-AR) and BN17 cells [endogenously express α2B (NG108) and transfected to express β2-AR] is due in part to increased GRK3 gene expression. In both cell lines, the increase in GRK3 transcription occurred via an extracellular signal-regulated kinase (ERK) 1/2-dependent mechanism because the increase in GRK3 mRNA is eliminated in the presence of the mitogen-activated protein kinase/ERK kinase 1/2 inhibitor, U0126 [1,4-diamino-2,3-dicyano-1,4-bis (2-amino phenylthiobutadiene)]. EPI-induced GRK3 mRNA up-regulation also is prevented in the presence of propranolol or phentolamine. Moreover, GRK3 mRNA did not increase in response to EPI treatment in NG108 cells (endogenously express α2B-AR with no β2-AR). Both these results suggest that simultaneous activation of α2- and β2-AR by EPI is required for the ERK1/2-dependent increase in GRK3 mRNA. The EPI-induced increase in GRK3 mRNA was unaffected in the presence of the protein kinase C inhibitor, chelerythrine chloride. Finally, EPI treatment resulted in increased nuclear translocation and accumulation of the transcription factors, Sp-1 and Ap-2, in BE(2)-C cells. Taken together, our results demonstrate the involvement of the ERK1/2 pathway in selective up-regulation of GRK3 mRNA expression, possibly via activation of Sp-1 and Ap-2 transcription factors in neuronal cells. The American Society for Pharmacology and Experimental Therapeutics