title: Calcineurin-mediated YB-1 dephosphorylation regulates CCL5 expression during monocyte differentiation.
abstract: Y-box (YB) protein-1 serves as a master regulator in gene transcription and mRNA translation. YB-1 itself is regulated at various levels, e.g. through post-translational modifications. In our previous work, we identified RANTES/CCL5 as a transcriptional target of YB-1. We previously demonstrated that YB-1 protein is transiently up-regulated during monocyte/macrophage differentiation evidenced in monocytic cells (THP-1 cells) that were differentiated using phorbol myristate acetate (PMA). Here we provide evidence that YB-1 phosphorylation, specifically at its serine residue 102 (Ser-102), increases early on in THP-1 cells following PMA treatment as well as in differentiated primary human monocytes. This process is mediated through the Akt signaling pathway. Ser-102-phosphorylated YB-1 displays stronger binding affinity and trans-activating capacity at the CCL5 gene promoter. Notably, Ser-102-phosphorylated YB-1 disappears at later stages of the monocyte/macrophage differentiation process. We demonstrate that serine-threonine phosphatase calcineurin (CN) dephosphorylates YB-1 preventing it from binding to and trans-activating the CCL5 promoter. Co-immunoprecipitation assays prove a direct YB-1/CN interaction. Furthermore, analyses in kidney tissues from mice that were treated with the CN inhibitor cyclosporine A revealed an in vivo effect of CN on the YB-1 phosphorylation status. We conclude that YB-1 phosphorylation at Ser-102 is an important prerequisite for CCL5 promoter activation during macrophage differentiation. Our findings point to a critical role of YB-1 in the resolution of inflammatory processes which may largely be due to CN-mediated dephosphorylation.
authors.affiliation: From the Department of Nephrology and Clinical Immunology, University Hospital RWTH-Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Alidousty
authors.affiliation: From the Department of Nephrology and Clinical Immunology, University Hospital RWTH-Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rauen
authors.affiliation: From the Department of Nephrology and Clinical Immunology, University Hospital RWTH-Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany.
authors.forename: Lydia
authors.initials: L
authors.lastname: Hanssen
authors.affiliation: the Department of Rheumatology, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: the Department of Cell and Molecular Biology, Institute of Biochemistry and Molecular Cell Biology, University Hospital RWTH-Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany, and.
authors.forename: Setareh
authors.initials: S
authors.lastname: Alampour-Rajabi
authors.affiliation: the Department of Nephrology, Hypertension, Diabetes, and Endocrinology, Otto-von-Guericke-University, 39120 Magdeburg, Germany.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Mertens
authors.affiliation: the Department of Cell and Molecular Biology, Institute of Biochemistry and Molecular Cell Biology, University Hospital RWTH-Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany, and.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Bernhagen
authors.affiliation: From the Department of Nephrology and Clinical Immunology, University Hospital RWTH-Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Floege
authors.affiliation: From the Department of Nephrology and Clinical Immunology, University Hospital RWTH-Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany.
authors.forename: Tammo
authors.initials: T
authors.lastname: Ostendorf
authors.affiliation: From the Department of Nephrology and Clinical Immunology, University Hospital RWTH-Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany, uraffetseder@ukaachen.de.
authors.forename: Ute
authors.initials: U
authors.lastname: Raffetseder
mesh_terms: D001483:Base Sequence; D019703:Calcineurin / Q000502:physiology*; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D018946:Chemokine CCL5 / Q000235:genetics*; D017931:DNA Primers; D006801:Humans; D009000:Monocytes / Q000166:cytology / Q000378:metabolism*; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D051840:Y-Box-Binding Protein 1 / Q000378:metabolism*
chemical_list: C483024:CCL5 protein, human; D018946:Chemokine CCL5; D017931:DNA Primers; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human; D019703:Calcineurin; D013755:Tetradecanoylphorbol Acetate
keywords: CCL5; Calcineurin; Chemokine; Gene Expression; Gene Regulation; Monocyte Differentiation; Phosphatase; Y-box Protein-1