title: Interleukins 2 and 15 regulate Ets1 expression via ERK1/2 and MNK1 in human natural killer cells.
abstract: Interleukins (IL)-2 and IL-15 regulate natural killer (NK) cell proliferation, survival, and cytolytic activity. Ets1 is a transcription factor expressed early in NK cell differentiation. Because IL-2Rbeta, IL-2Rgamma, IL-15, and Ets1 knock-out mice similarly lack NK cells, we explored a molecular connection between IL-2R signaling and Ets1. Here we report the post-transcriptional regulation of Ets1 by IL-2R signaling in human NK cells. IL-2 and IL-15 stimulation leads to increased Ets1 protein levels with no significant change in mRNA levels. Pulse and pulse-chase experiments show that IL-2 stimulation results in both a marked increase in the nascent translation of Ets1 and an increased protein half-life. Pharmacological inhibition of MEK specifically blocks IL-2- and IL-15-induced translation, whereas p38, phosphatidylinositol 3-kinase, and mTOR inhibitors had no effect on Ets1 levels. Fli1, an Ets family member, exhibited a different mechanism of regulation, illustrating the specificity of IL-2R beta and gamma subunit signaling on the regulation of Ets1 expression. Expression of a dominant negative form of MNK1, a regulator of the translation initiation factor eIF4E, blocks the expression of Ets1 as do the dominant negative forms of the common IL-2R beta and gamma chains. Expression of Ets1 is regulated similarly in normal peripheral human NK cells. Taken together, our findings provide a direct link between IL-2R subunit signaling and Ets1 expression and helps to explain the interdependence of the IL-2R subunits and Ets1 for NK cell development and function.
authors.affiliation: Department of Cell Biology and Anatomy, Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Grund
authors.forename: Demetri D
authors.initials: DD
authors.lastname: Spyropoulos
authors.forename: Dennis K
authors.initials: DK
authors.lastname: Watson
authors.forename: Robin C
authors.initials: RC
authors.lastname: Muise-Helmericks
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D015152:Blotting, Northern; D015153:Blotting, Western; D002454:Cell Differentiation; D002461:Cell Line, Transformed; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D015971:Gene Expression Regulation, Enzymologic; D005799:Genes, Dominant; D006801:Humans; D019409:Interleukin-15 / Q000378:metabolism / Q000502:physiology*; D007376:Interleukin-2 / Q000378:metabolism / Q000502:physiology*; D053646:Interleukin-2 Receptor beta Subunit; D047908:Intracellular Signaling Peptides and Proteins; D007694:Killer Cells, Natural / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D008954:Models, Biological; D010641:Phenotype; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D014176:Protein Biosynthesis; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D050783:Proto-Oncogene Proteins c-ets; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism; D018123:Receptors, Interleukin / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D014162:Transfection; D000077191:Wortmannin; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D000730:Androstadienes; D004791:Enzyme Inhibitors; D019409:Interleukin-15; D007376:Interleukin-2; D053646:Interleukin-2 Receptor beta Subunit; D047908:Intracellular Signaling Peptides and Proteins; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D015375:Receptors, Interleukin-2; D014157:Transcription Factors; D000077191:Wortmannin; D048051:p38 Mitogen-Activated Protein Kinases; C494041:ETS1 protein, human; C508020:IL2RB protein, human; C491395:MKNK1 protein, human