title: The interaction of PTP-BL PDZ domains with RIL: an enigmatic role for the RIL LIM domain.
abstract: PDZ domains are protein-protein interaction modules that are crucial for the assembly of structural and signaling complexes. PDZ domains specifically bind short carboxyl-terminal peptides and occasionally internal sequences that structurally resemble peptide termini. Previously, using yeast two-hybrid methodology, we studied the interaction of two PDZ domains present in the large submembranous protein tyrosine phosphatase PTP-BL with' the C-terminal half of the LIM domain-containing protein RIL. Deletion of the extreme RIL C-terminus did not eliminate binding, suggesting the presence of a PDZ binding site within the RIL LIM moiety. We have now performed experiments in mammalian cell lysates and found that the RIL C-terminus proper, but not the RIL LIM domain, can interact with PTP-BL, albeit very weakly. However, this interaction with PTP-BL PDZ domains is greatly enhanced when the combined RIL LIM domain and C-terminus is used, pointing to synergistic effects. NMR titration experiments and site-directed mutagenesis indicate that this result is not dependent on specific interactions that require surface exposed residues on the RIL LIM domain, suggesting a stabilizing role in the association with PTP-BL.
authors.affiliation: Department of Cell Biology, Nijmegen Center for Molecular Life Sciences, University of Nijmegen, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands.
authors.forename: Lieke C J
authors.initials: LC
authors.lastname: van den Berk
authors.forename: Marco A
authors.initials: MA
authors.lastname: van Ham
authors.forename: Mariska M
authors.initials: MM
authors.lastname: te Lindert
authors.forename: Tine
authors.initials: T
authors.lastname: Walma
authors.forename: Jan
authors.initials: J
authors.lastname: Aelen
authors.forename: Geerten W
authors.initials: GW
authors.lastname: Vuister
authors.forename: Wiljan J A J
authors.initials: WJ
authors.lastname: Hendriks
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002522:Chlorocebus aethiops; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D060588:LIM Domain Proteins; D051379:Mice; D008840:Microfilament Proteins; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D054595:Protein Tyrosine Phosphatase, Non-Receptor Type 13; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques
chemical_list: D004268:DNA-Binding Proteins; D060588:LIM Domain Proteins; D008840:Microfilament Proteins; C486248:Pdlim4 protein, mouse; D054595:Protein Tyrosine Phosphatase, Non-Receptor Type 13; D017027:Protein Tyrosine Phosphatases; C516743:Ptpn13 protein, mouse