title: Diacylglycerol kinase ζ controls diacylglycerol metabolism at the immunological synapse.
abstract: Diacylglycerol (DAG) generation at the T cell immunological synapse (IS) determines the correct activation of antigen-specific immune responses. DAG kinases (DGKs) α and ζ act as negative regulators of DAG-mediated signals by catalyzing DAG conversion to phosphatidic acid (PA). Nonetheless, the specific input of each enzyme and their spatial regulation during IS formation remain uncharacterized. Here we report recruitment of endogenous DGKα and DGKζ to the T cell receptor (TCR) complex following TCR/CD28 engagement. Specific DGK gene silencing shows that PA production at the activated complex depends mainly on DGKζ, indicating functional differences between these proteins. DGKζ kinase activity at the TCR is enhanced by phorbol-12-myristate-13-acetate cotreatment, suggesting DAG-mediated regulation of DGKζ responsiveness. We used GFP-DGKζ and -DGKα chimeras to assess translocation dynamics during IS formation. Only GFP-DGKζ translocated rapidly to the plasma membrane at early stages of IS formation, independent of enzyme activity. Finally, use of a fluorescent DAG sensor confirmed rapid, sustained DAG accumulation at the IS and allowed us to directly correlate membrane translocation of active DGKζ with DAG consumption at the IS. This study highlights a DGKζ-specific function for local DAG metabolism at the IS and offers new clues to its mode of regulation.
authors.affiliation: Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, E-28049 Madrid, Spain.
authors.forename: Severine I
authors.initials: SI
authors.lastname: Gharbi
authors.forename: Esther
authors.initials: E
authors.lastname: Rincón
authors.forename: Antonia
authors.initials: A
authors.lastname: Avila-Flores
authors.forename: Pedro
authors.initials: P
authors.lastname: Torres-Ayuso
authors.forename: María
authors.initials: M
authors.lastname: Almena
authors.forename: María Angeles
authors.initials: MA
authors.lastname: Cobos
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Albar
authors.forename: Isabel
authors.initials: I
authors.lastname: Mérida
mesh_terms: D018106:CD28 Antigens / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane; D019852:Diacylglycerol Kinase / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004075:Diglycerides / Q000378:metabolism*; D006801:Humans; D054992:Immunological Synapses / Q000378:metabolism*; D019169:Jurkat Cells; D010703:Phorbol Esters / Q000494:pharmacology; D010712:Phosphatidic Acids / Q000096:biosynthesis; D034622:RNA Interference; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D018106:CD28 Antigens; D004075:Diglycerides; D010703:Phorbol Esters; D010712:Phosphatidic Acids; D011948:Receptors, Antigen, T-Cell; C119222:phorbol-12-myristate; C526463:DGKZ protein, human; D019852:Diacylglycerol Kinase