The WW Domain of Yes-Associated Protein Binds a Proline-Rich Ligand that Differs from the Consensus Established for Src Homology 3-Binding Modules

• Published in: Proceedings of the National Academy of Sciences - PNAS 1995-08, Vol.92 (17), p.7819-7823
• Main Authors: Chen, Henry I., Sudol, Marius
• Format: Article
• Language: English
• Subjects: Adaptor Proteins, Signal Transducing; Amino Acid Sequence; Amino acids; Animals; Base Sequence; Binding Sites; Biochemistry; Carrier Proteins - biosynthesis; Carrier Proteins - chemistry; Carrier Proteins - metabolism; Cerebellum; Cerebellum - metabolism; Cloning, Molecular; Complementary DNA; Consensus Sequence; Conserved Sequence; DNA Primers; DNA, Complementary; Female; Gels; Gene Library; Glutathione Transferase - biosynthesis; Glutathione Transferase - metabolism; Humans; Ligands; Lung - metabolism; Lungs; Molecular Sequence Data; Molecules; Muscle, Skeletal - metabolism; Oligodeoxyribonucleotides; Open Reading Frames; Ovaries; Ovary - metabolism; Phosphoproteins - biosynthesis; Phosphoproteins - chemistry; Phosphoproteins - metabolism; Polymerase Chain Reaction; Proline; Proteins; Rats; Recombinant Fusion Proteins - biosynthesis; Recombinant Fusion Proteins - isolation & purification; Recombinant Fusion Proteins - metabolism; Restriction Mapping; Sequence Homology, Amino Acid; Skeletal muscle; Transcription Factors
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.92.17.7819

The WW domain has previously been described as a motif of 38 semiconserved residues found in seemingly unrelated proteins, such as dystrophin, Yes-associated protein (YAP), and two transcriptional regulators, Rsp-5 and FE65. The molecular function of the WW domain has been unknown until this time. Using a functional screen of a cDNA expression library, we have identified two putative ligands of the WW domain of YAP, which we named WBP-1 and WBP-2. Peptide sequence comparison between the two partial clones revealed a homologous region consisting of a proline-rich domain followed by a tyrosine residue (with the shared sequence PPPPY), which we shall call the PY motif. Binding assays and site-specific mutagenesis have shown that the PY motif binds with relatively high affinity and specificity to the WW domain of YAP, with the preliminary consensus XPPXY being critical for binding. Herein, we have implicated the WW domain with a role in mediating protein-protein interactions, as a variant of the paradigm set by Src homology 3 domains and their proline-rich ligands.