Characterization of a novel protein-binding module--the WW domain

FEBS Lett. 1995 Aug 1;369(1):67-71. doi: 10.1016/0014-5793(95)00550-s.


We have identified, characterized and cloned human, mouse and chicken cDNA of a novel protein that binds to the Src homology domain 3 (SH3) of the Yes proto-oncogene product. We subsequently named it YAP for Yes-associated protein. Analysis of the YAP sequence revealed a protein module that was found in various structural, regulatory and signaling molecules. Because one of the prominent features of this sequence motif is the presence of two conserved tryptophans (W), we named it the WW domain. 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 proline-rich region. Binding assays and site-specific mutagenesis have shown that the proline-rich motif binds with relatively high affinity and specificity to the WW domain of YAP, with a preliminary consensus that is different from the SH3-binding PXXP motif. This suggests that the WW domain has a role in mediating protein-protein interactions via proline-rich regions, similar but distinct from Src homology 3 (SH3) domains. Based on this finding, we hypothesize that additional protein modules exist and that they could be isolated using proline-rich peptides as functional probes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Adaptor Proteins, Signal Transducing*
  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Cycle Proteins
  • Humans
  • Ligands
  • Molecular Sequence Data
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Protein Binding
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins c-yes
  • Sequence Homology, Amino Acid
  • Transcription Factors
  • YAP-Signaling Proteins
  • src-Family Kinases*


  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Cell Cycle Proteins
  • Ligands
  • MAS1 protein, human
  • Phosphoproteins
  • Proto-Oncogene Mas
  • Proto-Oncogene Proteins
  • Transcription Factors
  • YAP-Signaling Proteins
  • YAP1 protein, human
  • Yap1 protein, mouse
  • Proto-Oncogene Proteins c-yes
  • src-Family Kinases