Extracellular Signal-Regulated Kinase 1/2-Mediated Transcriptional Regulation of G-Protein-Coupled Receptor Kinase 3 Expression in Neuronal Cells

Abstract

Relatively small changes in G-protein-coupled receptor kinase (GRK) 3 expression (ϳ2-fold) profoundly affect ␣ 2 -adrenergic receptor (AR) function and preferentially regulate neuronal ␣ 2A -and ␣ 2B -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 ␣ 2A -and ␤ 2 -AR) and BN17 cells [endogenously express ␣ 2B (NG108) and transfected to express ␤ 2 -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 upregulation 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 ␣ 2B -AR with no ␤ 2 -AR). Both these results suggest that simultaneous activation of ␣ 2 -and ␤ 2 -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.G-protein-coupled receptor kinases (GRKs) specifically interact with agonist-occupied G-protein-coupled receptors (GPCRs) to mediate receptor phosphorylation. This phosphorylation increases the affinity of the receptor for arrestin, and receptor/G-protein interaction is inhibited even in the presence of agonist. The resulting rapid loss of receptor responsiveness is termed desensitization and in many instances is followed by the removal of the receptor from the plasma membrane via clathrin-mediated endocytosis (Penn et al

Effects of the Dopamine D2 Allosteric Modulator, PAOPA, on the Expression of GRK2, Arrestin-3, ERK1/2, and on Receptor Internalization

“…Increased ERK1/2 levels can have a range of cellular effects. One particular study demonstrated the involvement of the ERK1/2 pathway in the upregulation of GRKs, via activation of Sp-1 and Ap-2 transcription factors in neuronal cells [55]. Increased arrestin-3 levels could also promote formation of another key scaffold complex, involving dephosphorylation and activation of Akt using PP2A.…”

Altered expression and subcellular distribution of GRK subtypes in the dopamine‐depleted rat basal ganglia is not normalized byl‐DOPA treatment

“…Rapid turnover of GRK2 is consistent with high mRNA : protein ratio observed in this work. Stimulation of alpha2‐ and beta2‐ adrenoreceptors is reported to up‐regulates GRK3 in neuronal cell lines in an ERK1/2‐dependent manner, possibly, via activation of Sp‐1 and Ap‐2 transcription factors (Salim et al. 2007).…”

G protein-coupled receptor kinases: More than just kinases and not only for GPCRs

“…Administration of GPCR antagonists or removal of endogenous agonists also can affect the GRK concentration (Hurle, 2001; Diaz et al, 2002; Bezard et al, 2005; Ahmed et al, 2007; Ahmed et al, 2008; Ahmed et al, 2010). The concentration of GRKs in vivo and in cultured cells is responsive to various conditions such as stress (Taneja et al, 2011), neonatal ventral hippocampal lesion (Bychkov et al, 2010), cell cycle progression (Penela et al, 2010), and drug treatment (Salim et al, 2007). Human diseases alter GRK levels.…”

“…Epinephrine acting simultaneously via α 2 - and β2ARs upregulates the level of GRK3 mRNA and protein in neuronal cell lines (Salim et al, 2007). The action of epinephrine is mediated by the activation of ERK1/2 and possibly transcription factors Sp-1 and Ap-2.…”