Diacylglycerol kinase inhibition prevents IL-2-induced G1 to S transition through a phosphatidylinositol-3 kinase-independent mechanism.
Stimulation via IL-2R ligation causes T lymphocytes to transit through the cell cycle. Previous experiments by our group have demonstrated that, in human T cells, IL-2 binding induces phosphatidic acid production through activation of the alpha isoform of diacylglycerol kinase. In this study, using the IL-2-dependent mouse T cell line CTLL-2, we demonstrate that pharmacological inhibition of IL-2-induced diacylglycerol kinase activation is found to block IL-2-induced late G1 to S transition without affecting cell viability. Herein, we demonstrate that diacylglycerol kinase inhibition has a profound effect on the induction of the protooncogenes c-myc, c-fos, and c-raf by IL-2, whereas expression of bcl-2 and bcl-xL are not affected. When the IL-2-regulated cell cycle control checkpoints are examined in detail, we demonstrate that inhibition of diacylglycerol kinase activation prevents IL-2 induction of cyclin D3 without affecting p27 down-regulation. The strict control of cell proliferation exerted by phosphatidic acid through activation of diacylglycerol kinase is independent of other well-characterized IL-2R-derived signals, such as the phosphatidylinositol-3 kinase/Akt pathway, indicating the existence of a different and important mechanism to control cell division.
Department of Immunology and Oncology, Centro Nacional de Biotecnología, Madrid, Spain.
I
I
Flores
D R
DR
Jones
A
A
Ciprés
E
E
Díaz-Flores
M A
MA
Sanjuan
I
I
Mérida
D000818:Animals; D002453:Cell Cycle / Q000187:drug effects / Q000276:immunology; D018797:Cell Cycle Proteins; D002460:Cell Line; D016895:Culture Media, Serum-Free; D056743:Cyclin D3; D050760:Cyclin-Dependent Kinase Inhibitor p27; D016213:Cyclins / Q000378:metabolism; D019852:Diacylglycerol Kinase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects / Q000276:immunology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016193:G1 Phase / Q000187:drug effects / Q000276:immunology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology; D007376:Interleukin-2 / Q000502:physiology*; D015847:Interleukin-4 / Q000037:antagonists & inhibitors / Q000502:physiology; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism / Q000502:physiology*; D010880:Piperidines / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D011519:Proto-Oncogenes / Q000187:drug effects / Q000276:immunology; D011799:Quinazolines / Q000494:pharmacology; D052999:Quinazolinones; D016160:Retinoblastoma Protein / Q000378:metabolism; D016196:S Phase / Q000187:drug effects / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D025521:Tumor Suppressor Proteins
D018797:Cell Cycle Proteins; D016895:Culture Media, Serum-Free; D056743:Cyclin D3; D050760:Cyclin-Dependent Kinase Inhibitor p27; D016213:Cyclins; D019852:Diacylglycerol Kinase; D004791:Enzyme Inhibitors; D007376:Interleukin-2; D015847:Interleukin-4; D008869:Microtubule-Associated Proteins; D019869:Phosphatidylinositol 3-Kinases; D010880:Piperidines; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D011799:Quinazolines; D052999:Quinazolinones; D016160:Retinoblastoma Protein; D025521:Tumor Suppressor Proteins; C534696:CCND3 protein, human; C534697:Ccnd3 protein, mouse; C493961:Cdkn1b protein, mouse; C058544:R 59949