The interaction of PTP-BL PDZ domains with RIL: an enigmatic role for the RIL LIM domain.
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.
van den Berk
Lieke C J
LC
Department of Cell Biology, Nijmegen Center for Molecular Life Sciences, University of Nijmegen, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands.
van Ham
Marco A
MA
te Lindert
Mariska M
MM
Walma
Tine
T
Aelen
Jan
J
Vuister
Geerten W
GW
Hendriks
Wiljan J A J
WJ
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
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