Inventors:
Jacqueline F. Bromberg - New York NY
Melissa H. Wrzeszczynska - New York NY
Yanxiang Zhao - New York NY
James E. Darnell - Larchmont NY
Assignee:
The Rockefeller University - New York NY
International Classification:
A61K 3800, C07K 1400, C08G 6926, C07H 2102
Abstract:
The invention is directed to constitutively active Stat proteins and methods for their preparation. The modified Stat proteins have at least one cysteine residue which may interact with the corresponding cysteine residue on another modified Stat protein to form a dimer. The constitutively active Stat proteins are capable of binding to DNA and activating transcription in the absence of tyrosine phosphorylation. Cell lines expressing the modified Stat protein exhibit a transformed phenotype and are capable of forming tumors in nude mice. Methods are describe utilizing the modified Stat proteins of the invention in the absence and presence of tyrosine phosphorylation in identifying agents capable of modulating Stat protein dimerization, transcriptional activity, and cellular transformation in vitro and in vivo. The invention is also directed to polynucleotides encoding modified, constitutively active Stat proteins.