Abstract
Signal transducing adaptor protein-2 (STAP-2) is a recently identified adaptor protein that contains Pleckstrin and Src homology 2 (SH2)-like domains as well as a YXXQ motif in its C-terminal region. Our previous studies revealed that STAP-2 binds to signal transducer and activator of transcription 3 (STAT3) and STAT5, and regulates their signaling pathways. In the present study, we identified tyrosine-250 (Tyr250) in STAP-2 as a major site of phosphorylation by v-src and Jak2, using a phospho-specific antibody against STAP-2 phosphorylated at Tyr250. Mutational analyses revealed that Tyr250 was involved in the STAT3-enhancing activity of STAP-2. We further found that leukemia inhibitory factor (LIF) stimulated STAP-2 Tyr250 phosphorylation in 293T and Hep3B cells. Moreover, endogenous STAP-2 was phosphorylated at Tyr250 following LIF stimulation of murine M1 cell line. Taken together, our findings demonstrate that endogenous STAP-2 is phosphorylated at Tyr250 and that this phosphorylation is involved in its function.
Original language | English |
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Pages (from-to) | 517-522 |
Number of pages | 6 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 356 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2007 May 4 |
Externally published | Yes |
Keywords
- Adaptor protein
- Antibody
- LIF
- Phosphorylation
- STAP-2
- STAT3
- Transcription
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology