title: RNA-binding protein HuR regulates RGS4 mRNA stability in rabbit colonic smooth muscle cells.
abstract: Regulator of G protein signaling 4 (RGS4) regulates the strength and duration of G protein signaling and plays an important role in smooth muscle contraction, cardiac development, and psychiatric disorders. Little is known about the posttranscriptional regulation of RGS4 expression. We cloned the full-length cDNA of rabbit RGS4, which contains a long 3'-untranslated region (UTR) with several AU-rich elements (AREs). We determined whether RGS4 mRNA stability is mediated by the RNA-binding protein human antigen R (HuR) and contributes to IL-1β-induced upregulation of RGS4 expression. We show that IL-1β treatment in colonic smooth muscle cells doubled the half-life of RGS4 mRNA. Addition of RGS4 3'-UTR to the downstream of Renilla luciferase reporter induced dramatic reduction in the enzyme activity and mRNA expression of luciferase, which was attenuated by the site-directed mutation of the two 3'-most ARE sites. IL-1β increased luciferase mRNA stability in a UTR-dependent manner. Knockdown of HuR significantly aggravated UTR-mediated instability of luciferase and inhibited IL-1β-induced upregulation of RGS4 mRNA. In addition, IL-1β increased cytosolic translocation and RGS4 mRNA binding of HuR. These findings suggest that 3'-most ARE sites within RGS4 3'-UTR are essential for the instability of RGS4 mRNA and IL-1β promotes the stability of RGS4 mRNA through HuR.
authors.affiliation: Department of Neuroscience, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Danielle Y
authors.initials: DY
authors.lastname: Hu
authors.forename: Shu
authors.initials: S
authors.lastname: Liu
authors.forename: Sunila
authors.initials: S
authors.lastname: Mahavadi
authors.forename: William
authors.initials: W
authors.lastname: Yen
authors.forename: Karnam S
authors.initials: KS
authors.lastname: Murthy
authors.forename: Kamel
authors.initials: K
authors.lastname: Khalili
authors.forename: Wenhui
authors.initials: W
authors.lastname: Hu
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D000954:Antigens, Surface / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003106:Colon / Q000378:metabolism*; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism* / Q000494:pharmacology; D008969:Molecular Sequence Data; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D020710:RGS Proteins / Q000235:genetics / Q000378:metabolism*; D020871:RNA Stability; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits; D015854:Up-Regulation
chemical_list: D020413:3' Untranslated Regions; D000954:Antigens, Surface; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; C098770:ELAVL1 protein, human; D053583:Interleukin-1beta; D020710:RGS Proteins; D016601:RNA-Binding Proteins; C098799:RGS4 protein