Fig. 9. Schematic model of RPTPß/Slipr complex. The C-terminal tail of RPTPß binds to the third PDZ domain of Slipr/MAGI-3. This interaction brings the phosphatase into proximity with its tyrosine phosphorylated p130 substrate, resulting in dephosphorylation of p130. Since the molecular identity of p130 is not known, it was arbitrarily drawn bound to one PDZ and one WW domain. It is likely that the multi-domain organization of MAGI-3 allows it to bind simultaneously to other proteins in addition to RPTPß and p130, generating a signaling complex at the plasma membrane.