| First Author | Cuppen E | Year | 1998 |
| Journal | Mol Biol Cell | Volume | 9 |
| Issue | 3 | Pages | 671-83 |
| PubMed ID | 9487134 | Mgi Jnum | J:60719 |
| Mgi Id | MGI:1353830 | Doi | 10.1091/mbc.9.3.671 |
| Citation | Cuppen E, et al. (1998) PDZ motifs in PTP-BL and RIL bind to internal protein segments in the LIM domain protein RIL. Mol Biol Cell 9(3):671-83 |
| abstractText | The specificity of protein-protein interactions in cellular signaling cascades is dependent on the sequence and intramolecular location of distinct amino acid motifs. We used the two-hybrid interaction trap to identify proteins that can associate with the PDZ motif-rich segment in the protein tyrosine phosphatase PTP-BL. A specific interaction was found with the Lin-11, Isl-1, Mec-3 (LIM) domain containing protein RIL. More detailed analysis demonstrated that the binding specificity resides in the second and fourth PDZ motif of PTP-BL and the LIM domain in RIL. Immunohistochemistry on various mouse tissues revealed a submembranous colocalization of PTP-BL and RIL in epithelial cells. Remarkably, there is also an N-terminal PDZ motif in RIL itself that can bind to the RIL-LIM domain. We demonstrate here that the RIL-LIM domain can be phosphorylated on tyrosine in vitro and in vivo and can be dephosphorylated in vitro by the PTPase domain of PTP-BL. Our data point to the presence of a double PDZ-binding interface on the RIL-LIM domain and suggest tyrosine phosphorylation as a regulatory mechanism for LIM-PDZ associations in the assembly of multiprotein complexes. These findings are in line with an important role of PDZ-mediated interactions in the shaping and organization of submembranous microenvironments of polarized cells. |
