title: PKA regulates calcineurin function through the phosphorylation of RCAN1: identification of a novel phosphorylation site.
abstract: Calcineurin is a calcium/calmodulin-dependent phosphatase that has been implicated in T cell activation through the induction of nuclear factors of activated T cells (NFAT). We have previously suggested that endogenous regulator of calcineurin (RCAN1, also known as DSCR1) is targeted by protein kinase A (PKA) for the control of calcineurin activity. In the present study, we characterized the PKA-mediated phosphorylation site in RCAN1 by mass spectrometric analysis and revealed that PKA directly phosphorylated RCAN1 at the Ser 93. PKA-induced phosphorylation and the increase in the half-life of the RCAN1 protein were prevented by the substitution of Ser 93 with Ala (S93A). Furthermore, the PKA-mediated phosphorylation of RCAN1 at Ser 93 potentiated the inhibition of calcineurin-dependent pro-inflammatory cytokine gene expression by RCAN1. Our results suggest the presence of a novel phosphorylation site in RCAN1 and that its phosphorylation influences calcineurin-dependent inflammatory target gene expression.
authors.affiliation: Department of Molecular Bioscience, College of Biomedical Science, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 200-701, Republic of Korea.
authors.forename: Seon Sook
authors.initials: SS
authors.lastname: Kim
authors.affiliation: Department of Molecular Bioscience, College of Biomedical Science, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 200-701, Republic of Korea.
authors.forename: Eun Hye
authors.initials: EH
authors.lastname: Lee
authors.affiliation: Department of Bio-Health Technology, College of Biomedical Science, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 200-701, Republic of Korea.
authors.forename: Kooyeon
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Physiology, BK21 Plus Graduate Program, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 200-701, Republic of Korea. Electronic address: suhyunjo@kangwon.ac.kr.
authors.forename: Su-Hyun
authors.initials: SH
authors.lastname: Jo
authors.affiliation: Department of Molecular Bioscience, College of Biomedical Science, Institute of Bioscience & Biotechnology, Kangwon National University, Chuncheon 200-701, Republic of Korea. Electronic address: suryeonseo@kangwon.ac.kr.
authors.forename: Su Ryeon
authors.initials: SR
authors.lastname: Seo
mesh_terms: D000595:Amino Acid Sequence; D019703:Calcineurin / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004268:DNA-Binding Proteins; D057809:HEK293 Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation
chemical_list: D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009124:Muscle Proteins; C108612:RCAN1 protein, human; D017868:Cyclic AMP-Dependent Protein Kinases; D019703:Calcineurin
keywords: Calcineurin; Inflammation; PKA; Phosphorylation; RCAN1