title: Nuclear diacylglycerol kinase-theta is activated in response to nerve growth factor stimulation of PC12 cells.
abstract: Previous evidence from independent laboratories has shown that the nucleus contains diacylglycerol kinase (DGK) isoforms, i.e., the enzymes, which yield phosphatidic acid from diacylglycerol, thus terminating protein kinase C-mediated signaling events. A DGK isoform, which resides in the nucleus of PC12 cells, is DGK-theta. Here, we show that nerve growth factor (NGF) treatment of serum-starved PC12 cells results in the stimulation of both a cytoplasmic and a nuclear DGK activity. However, time course analysis shows that cytoplasmic DGK activity peaked earlier than its nuclear counterpart. While nuclear DGK activity was dramatically down-regulated by a monoclonal antibody known for selectively inhibiting DGK-theta, cytoplasmic DGK activity was not. Moreover, nuclear DGK activity was stimulated by phosphatidylserine, an anionic phospholipid that had no effect on cytoplasmic DGK activity. Upon NGF stimulation, the amount and the activity of DGK-theta, which was bound to the insoluble nuclear matrix fraction, substantially increased. Epidermal growth factor up-regulated a nuclear DGK activity insensitive to anti-DGK-theta monoclonal antibody. Overall, our findings identify nuclear DGK-theta as a down-stream target of NGF signaling in PC12 cells.
authors.affiliation: Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Cell Signalling Laboratory, Università degli Studi di Bologna, via Irnerio 48, 40126, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Tabellini
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Billi
authors.forename: Federica
authors.initials: F
authors.lastname: Falà
authors.forename: Alessandra
authors.initials: A
authors.lastname: Cappellini
authors.forename: Camilla
authors.initials: C
authors.lastname: Evagelisti
authors.forename: Lucia
authors.initials: L
authors.lastname: Manzoli
authors.forename: Lucio
authors.initials: L
authors.lastname: Cocco
authors.forename: Alberto Maria
authors.initials: AM
authors.lastname: Martelli
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D019852:Diacylglycerol Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D020932:Nerve Growth Factor / Q000378:metabolism* / Q000494:pharmacology; D015530:Nuclear Matrix / Q000187:drug effects / Q000378:metabolism; D016716:PC12 Cells; D010712:Phosphatidic Acids / Q000378:metabolism; D010718:Phosphatidylserines / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D016895:Culture Media, Serum-Free; D007527:Isoenzymes; D010712:Phosphatidic Acids; D010718:Phosphatidylserines; D020932:Nerve Growth Factor; D019852:Diacylglycerol Kinase