Signal transduction from type I and type II cytokine receptors plays important roles in development and function of cells regulating immune system. Although accumulating evidence suggests importance of Jak-Stat pathways in cytokine signal transduction, our earlier studies and other reports demonstrated that lymphocytes can differentiate and function even in the absence of the activation of Stat proteins, leading to a hypothesis that Stat-independent signaling pathways may play important roles in lymphocyte differentiation and function. However, the molecular nature of Stat-independent pathways is still elusive. The objective of the present research is to elucidate these elusive signaling pathways by using a novel expression cloning system, inducible translocation trap (ITT). ITT is based on translocation of a fusion protein consisting of LexA DNA-binding domain, transactivation domain of a strong transcriptional activator and a test molecule. LexA-mediated reporter gene expression is detected by flow cytometry. This system will be employed to analyze Stat-independent pathways in interferon gamma, as well as interleukin (IL)-2 and IL-3 signaling. The initial screening of cDNA library revealed that an isoform of pyruvate kinase (M2-PK), a key enzyme in glycolysis, translocates into the nucleus following IL-3 stimulation. In addition, it was found that the nuclear M2-PK plays an important role in cell proliferation. Molecular mechanisms of IL-3-induced nuclear translocation of M2-PK and enhancement of cell proliferation by the nuclear M2-PK will be analyzed by using molecular and cell biological techniques. Detailed information gained from the proposed experiments will be valuable for elucidation of molecular mechanisms of oncogenesis and autoimmune diseases caused by dysregulation of cytokine signaling.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI059315-03
Application #
7148084
Study Section
Cellular and Molecular Immunology - B (CMI)
Program Officer
Nasseri, M Faraz
Project Start
2004-12-01
Project End
2007-11-30
Budget Start
2006-12-01
Budget End
2007-11-30
Support Year
3
Fiscal Year
2007
Total Cost
$320,485
Indirect Cost
Name
New York University
Department
Pathology
Type
Schools of Medicine
DUNS #
121911077
City
New York
State
NY
Country
United States
Zip Code
10016
Saint Fleur, Shella; Hoshino, Akemi; Kondo, Kimie et al. (2009) Regulation of Fas-mediated immune homeostasis by an activation-induced protein, Cyclon. Blood 114:1355-65
Wang, Rui; Kozhaya, Lina; Mercer, Frances et al. (2009) Expression of GARP selectively identifies activated human FOXP3+ regulatory T cells. Proc Natl Acad Sci U S A 106:13439-44
Fujii, Hodaka; Hoshino, Akemi (2009) Lack of nuclear translocation of cytoplasmic domains of IL-2/IL-15 receptor subunits. Cytokine 46:302-8
Wang, Rui; Wan, Qi; Kozhaya, Lina et al. (2008) Identification of a regulatory T cell specific cell surface molecule that mediates suppressive signals and induces Foxp3 expression. PLoS One 3:e2705
Saint Fleur, Shella; Fujii, Hodaka (2008) Cytokine-induced nuclear translocation of signaling proteins and their analysis using the inducible translocation trap system. Cytokine 41:187-97
Hoshino, Akemi; Fujii, Hodaka (2007) Temporal regulation of Stat5 activity in determination of cell differentiation program. Biochem Biophys Res Commun 358:914-9
Hoshino, Akemi; Fujii, Hodaka (2007) Redundant promoter elements mediate IL-3-induced expression of a novel cytokine-inducible gene, cyclon. FEBS Lett 581:975-80
Fujii, Hodaka (2007) Cell type-specific roles of Jak3 in IL-2-induced proliferative signal transduction. Biochem Biophys Res Commun 354:825-9
Hoshino, Akemi; Hirst, John A; Fujii, Hodaka (2007) Regulation of cell proliferation by interleukin-3-induced nuclear translocation of pyruvate kinase. J Biol Chem 282:17706-11
Hoshino, Akemi; Fujii, Hodaka (2007) Nuclear translocation of 2-amino-3-ketobutyrate coenzyme A ligase by cold and osmotic stress. Cell Stress Chaperones 12:186-91

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