Premium
Stimulation of hTAF II 68 (NTD)‐mediated transactivation by v‐Src
Author(s) -
Lee Hye Jin,
Kim Sol,
Pelletier Jerry,
Kim Jungho
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(04)00314-x
Subject(s) - transactivation , proto oncogene tyrosine protein kinase src , tyrosine , ectopic expression , tyrosine phosphorylation , biology , phosphorylation , tyrosine kinase , sh2 domain , sh3 domain , microbiology and biotechnology , mutant , transcription factor , signal transduction , chemistry , biochemistry , gene
The three genes hTAF II 68 , EWS , and TLS (called the TET family) encode related RNA binding proteins containing an RNA recognition motif and three glycine‐, arginine‐, and proline‐rich regions in the C‐terminus and a degenerated repeat containing the consensus sequence Ser‐Tyr‐Gly‐Gln‐Ser in the N‐terminus. In many human cancers, the N‐terminal portion of hTAF II 68, EWS, or TLS is fused to the DNA binding domain of one of several transcription factors including Fli‐1, ERG, ETV1, E1AF, WT1, ATF‐1, CHOP, or TEC. We have recognized the presence of several potential tyrosine phosphorylation sites within the amino‐terminal domain of hTAF II 68 and have investigated the potential effects of cytoplasmic signaling on hTAF II 68 function. Herein, we find that hTAF II 68 is phosphorylated on tyrosine residue(s) by ectopic expression of v‐Src protein tyrosine kinase in vitro and in vivo. The hTAF II 68 protein can associated with the SH3 domains of several cell signaling proteins, including v‐Src protein tyrosine kinase. We also document that full‐length v‐Src can stimulate hTAF II 68‐mediated transcriptional activation, whereas deletion mutants of v‐Src are unable to exert this effect. In addition, cellular Src activity appears important for hTAF II 68 function since hTAF II 68‐mediated transactivation is reduced in a dose‐dependent fashion by ectopic overexpression of a dominant‐negative mutant of Src. Taken together, our results suggest that the biological activities of hTAF II 68 are linked to the cytoplasmic Src signal transduction pathway.