TI  - Use of the two hybrid system to detect the association of the
      protein-tyrosine-phosphatase,  <prot>SHPTP2</prot> , with another SH2-containing protein,
       <prot>Grb7</prot> .
PG  - 1537-44
AB  - <prot>SHPTP2</prot> is a ubiquitously-expressed SH2-containing tyrosine phosphatase
      that is tyrosine phosphorylated in response to activation of various
      receptor and nonreceptor tyrosine kinases.  <prot>SHPTP2</prot>  associates with the
       <prot><prot>platelet-derived growth factor</prot> (<prot>PDGF</prot>) receptor</prot>  after ligand stimulation,
      and binding of <prot>SHPTP2</prot> to this receptor promotes tyrosine phosphorylation
      of <prot>SHPTP2</prot>. The yeast two-hybrid system was modified to identify partners
      of tyrosine-phosphorylated proteins. Using <prot>SHPTP2</prot> as bait and supplying an
      exogenous tyrosine kinase gene to the yeast cells, we have found that
       <prot>SHPTP2</prot>  interacts with another signaling protein,  <prot>Grb7</prot> . We have localized
      the region of interaction to tyrosine 580 in the carboxyl end of <prot>SHPTP2</prot>
      and to the SH2 domain in the carboxy-terminus of <prot>Grb7</prot>. We demonstrate that
       <prot>Grb7</prot>  binds to  <prot>SHPTP2</prot>  in vitro under conditions where the latter is
      tyrosine-phosphorylated. These experiments show that this modified two
      hybrid technique may be useful for the identification of proteins involved
      in tyrosine kinase signal transduction cascades.
AD  - Fred Hutchinson Cancer Research Center, Seattle, Washington 98104, USA.
