A novel regulatory role of RGS4 in STAT5B activation, neurite outgrowth and neuronal differentiation. (1st May 2017)

• Record Type: Journal Article
• Authors: Pallaki, Paschalina; Georganta, Eirini-Maria; Serafimidis, Ioannis; Papakonstantinou, Maria-Pagona; Papanikolaou, Vassilis; Koutloglou, Sofia; Papadimitriou, Elsa; Agalou, Adamantia; Tserga, Aggeliki; Simeonof, Alexandra; Thomaidou, Dimitra; Gaitanou, Maria; Georgoussi, Zafiroula
• Is Part Of: Neuropharmacology. Volume 117(2017)
• Page Start: 408
• Page End: 421
• Publication Date: 2017-05-01
• Subjects: Differentiation -- Erythropoietin -- Neurite outgrowth -- Opioid receptor -- RGS4 -- STAT5B; DMEM Dulbecco's modified Eagle's medium -- EGTA ethylene glycol-bis(β-aminoethyl ether)-N, N, N′, N′-tetraacetic acid -- GPCR G protein-coupled receptors -- GAS γ interferon activated sequence -- FBS fetal bovine serum -- RGS Regulators of G protein Signalling -- ΔΝRGS4 RGS4 lacking its N-terminal domain -- 6xHis hexahistidine -- aa amino acids -- PH3 Phospho-Histone H3 -- δ-OR δ-opioid receptor -- DSLET [D-Ser2, Leu5, Thr6] enkephalin -- GST glutathione-S-transferase -- HA hemaglutinin -- MAPK mitogen activated protein kinase -- μ-OR μ-opioid receptor -- NRS normal rabbit serum -- NPCs neural precursor cells -- PBS phosphate-buffered saline -- PMSF phenylmethylsulfonyl fluoride -- PTX Bordetella pertussis toxin -- PVDF membrane polyvinylidene difluoride membrane -- STAT Signal Transducer and Activator of Transcription -- SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis -- SVZ subventricular zone; [D-Ser2, Leu5, Thr6]-enkephalin (PubChem CID: 107847) -- [3H]-diprenorphine (PubChem CID: 71719127) -- Retinoic acid (PubChem CID: 444795) -- Triton X-100 (PubChem CID: 5590) -- Deoxycholate (PubChem CID: 91896239) -- Sodium orthovanadate (PubChem CID: 6167) -- PMSF (PubChem CID: 4784) -- MgCl2(PubChem CID:5360315); Neuropsychopharmacology -- Periodicals; Autonomic Agents -- Periodicals; Neuropsychopharmacologie -- Périodiques; Neuropsychopharmacology; Periodicals; Electronic journals; 615.78
• DOI: 10.1016/j.neuropharm.2017.02.012
• Languages: English
• ISSNs: 0028-3908

Abstract

Abstract: The Regulator of G protein Signalling 4 (RGS4) is a multitask protein that interacts with and negatively modulates opioid receptor signalling. Previously, we showed that the δ-opioid receptor (δ-OR) forms a multiprotein signalling complex consisting of Gi/Go proteins and the Signal Transducer and Activator of Transcription 5B (STAT5B) that leads to neuronal differentiation and neurite outgrowth upon δ-ΟR activation. Here, we investigated whether RGS4 could participate in signalling pathways to regulate neurotropic events. We demonstrate that RGS4 interacts directly with STAT5B independently of δ-ΟR presence both in vitro and in living cells. This interaction involves the N-terminal portion of RGS4 and the DNA-binding SH3 domain of STAT5B. Expression of RGS4 in HEK293 cells expressing δ-OR and/or erythropoietin receptor results in inhibition of [D-Ser 2, Leu 5, Thr 6 ]-enkephalin (DSLET)-and erythropoietin-dependent STAT5B phosphorylation and subsequent transcriptional activation. DSLET-dependent neurite outgrowth of neuroblastoma cells is also blocked by RGS4 expression, whereas primary cortical cultures of RGS4 knockout mice ( RGS4 -/- ) exhibit enhanced neuronal sprouting after δ-OR activation. Additional studies in adult brain extracts from RGS4 -/- mice revealed increased levels of p-STAT5B. Finally, neuronal progenitor cultures from RGS4 -/- mice exhibit enhanced proliferation with concomitant increases in the mRNA levels of the anti-apoptotic STAT5B target genes bcl2 and bcl-xl . These observations suggest that RGS4 is implicated in opioid dependent neuronal differentiation and neurite outgrowth via a "non-canonical" signaling pathway regulating STAT5B-directed responses. Highlights: RGS4 selectively interacts with STAT5B. RGS4 inhibits opioid and erythropoietin STAT5B transcriptional responses. RGS4 is implicated δ-opioid dependent neuronal outgrowth and differentiation. RGS4 is implicated in neural stem cell proliferation and survival.