The experiments described in this proposal deal with the action on animal cells of extracellular signalling polypeptides through a newly discovered signalling pathway, the JAKSTAT pathway. First uncovered by studying the molecular mechanism of action of interferon alpha and gamma, this pathway is now known to be the direct route by which many different cytokine and growth factors bound to their cognate receptors at the cell surface activate transcription of specific genes in the cell nucleus. This gene activation is usually transient with long lasting effects on cells due to a cascade of events dependent on the first round of gene activation. The specific experiments proposed will advance knowledge of the physical and biochemical properties of the STAT proteins, so-called because they carry out the dual function of signal transduction and activators of transcription. The first two of these proteins to be recognized, Stat1 and Stat2, will be studied intensively to determine specific amino acid contact sites for homo- and heterodimerization, a necessary step in activation, for precise amino acid DNA contact sites and for contact sites with proteins in the transcriptional machinery. Crystallographic analysis of a portion (amino acids 133-712) of Stat1 will be carried out. The mechanism of inactivation of the activated STATs, which occurs within a few minutes to a few hours will be investigated to determine whether nuclear dephosphorylation or protein turnover occurs. Among the most important biologic events concerned with signalling from the cell surface are growth control and differentiation. STAT activation functions in both events and will be studied in both contexts. IFN-alpha and gamma block entry of cells into the S phase and the IFN-alpha and gamma sensitive genes contributing to cell growth restraint will be identified. Finally, genetic and biochemical studies of development is most advanced using Drosophila and we have discovered the first Drosophila Stat molecule that will be studied for its role in developmental pathways. Because many cytokines and growth factors that are crucial in inflammation, immunity, growth regulation and normal development act through this pathway these studies have obvious implication in human disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI032489-09
Application #
2886742
Study Section
Molecular Biology Study Section (MBY)
Program Officer
Gaither, Thelma A
Project Start
1991-08-01
Project End
2001-05-31
Budget Start
1999-06-01
Budget End
2000-05-31
Support Year
9
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Rockefeller University
Department
Anatomy/Cell Biology
Type
Other Domestic Higher Education
DUNS #
071037113
City
New York
State
NY
Country
United States
Zip Code
10065
Ahmed, Simi T; Darnell Jr, James E (2009) Serpin B3/B4, activated by STAT3, promote survival of squamous carcinoma cells. Biochem Biophys Res Commun 378:821-5
Betz, Aurel; Ryoo, Hyung Don; Steller, Hermann et al. (2008) STAT92E is a positive regulator of Drosophila inhibitor of apoptosis 1 (DIAP/1) and protects against radiation-induced apoptosis. Proc Natl Acad Sci U S A 105:13805-10
Ginsberg, Michael; Czeko, Elmar; Muller, Patrick et al. (2007) Amino acid residues required for physical and cooperative transcriptional interaction of STAT3 and AP-1 proteins c-Jun and c-Fos. Mol Cell Biol 27:6300-8
Mertens, Claudia; Zhong, Minghao; Krishnaraj, Ravi et al. (2006) Dephosphorylation of phosphotyrosine on STAT1 dimers requires extensive spatial reorientation of the monomers facilitated by the N-terminal domain. Genes Dev 20:3372-81
Shen, Yuhong; La Perle, Krista M D; Levy, David E et al. (2005) Reduced STAT3 activity in mice mimics clinical disease syndromes. Biochem Biophys Res Commun 330:305-9
Paz, Keren; Socci, Nicholas D; van Nimwegen, Erik et al. (2004) Transformation fingerprint: induced STAT3-C, v-Src and Ha-Ras cause small initial changes but similar established profiles in mRNA. Oncogene 23:8455-63
Shen, Yuhong; Schlessinger, Karni; Zhu, Xuejun et al. (2004) Essential role of STAT3 in postnatal survival and growth revealed by mice lacking STAT3 serine 727 phosphorylation. Mol Cell Biol 24:407-19
Yang, Edward; Lerner, Lorena; Besser, Daniel et al. (2003) Independent and cooperative activation of chromosomal c-fos promoter by STAT3. J Biol Chem 278:15794-9
Yang, Edward; van Nimwegen, Erik; Zavolan, Mihaela et al. (2003) Decay rates of human mRNAs: correlation with functional characteristics and sequence attributes. Genome Res 13:1863-72
Lerner, Lorena; Henriksen, Melissa A; Zhang, Xiaokui et al. (2003) STAT3-dependent enhanceosome assembly and disassembly: synergy with GR for full transcriptional increase of the alpha 2-macroglobulin gene. Genes Dev 17:2564-77

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