title: Distinct ligand preferences of Src homology 3 domains from Src, Yes, Abl, Cortactin, p53bp2, PLCgamma, Crk, and Grb2.
abstract: Src homology 3 (SH3) domains are conserved protein modules 50-70 amino acids long found in a variety of proteins with important roles in signal transduction. These domains have been shown to mediate protein-protein interactions by binding short proline-rich regions in ligand proteins. However, the ligand preferences of most SH3 domains and the role of these preferences in regulating SH3-mediated protein-protein interactions remain poorly defined. We have used a phage-displayed library of peptides of the form X6PXXPX6 to identify ligands for eight different SH3 domains. Using this approach, we have determined that each SH3 domain prefers peptide ligands with distinct sequence characteristics. Specifically, we have found that the Src SH3 domain selects peptides sharing the consensus motif LXXRPLPXpsiP, whereas Yes SH3 selects psiXXRPLPXLP, Abl SH3 selects PPXthetaXPPPpsiP, Cortactin SH3 selects +PPpsiPXKPXWL, p53bp2 SH3 selects RPXpsiPpsiR+SXP, PLCgamma SH3 selects PPVPPRPXXTL, Crk N-terminal SH3 selects psiPpsiLPpsiK, and Grb2 N-terminal SH3 selects +thetaDXPLPXLP (where psi, theta, and + represent aliphatic, aromatic, and basic residues, respectively). Furthermore, we have compared the binding of phage expressing peptides related to each consensus motif to a panel of 12 SH3 domains. Results from these experiments support the ligand preferences identified in the peptide library screen and evince the ability of SH3 domains to discern subtle differences in the primary structure of potential ligands. Finally, we have found that most known SH3-binding proteins contain proline-rich regions conforming to the ligand preferences of their respective SH3 targets.
authors.affiliation: Department of Biology, University of North Carolina, Chapel Hill, 27599, USA.
authors.forename: A B
authors.initials: AB
authors.lastname: Sparks
authors.forename: J E
authors.initials: JE
authors.lastname: Rider
authors.forename: N G
authors.initials: NG
authors.lastname: Hoffman
authors.forename: D M
authors.initials: DM
authors.lastname: Fowlkes
authors.forename: L A
authors.initials: LA
authors.lastname: Quillam
authors.forename: B K
authors.initials: BK
authors.lastname: Kay
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins / Q000378:metabolism; D016384:Consensus Sequence; D051356:Cortactin; D051380:GRB2 Adaptor Protein; D007527:Isoenzymes / Q000378:metabolism; D008024:Ligands; D008840:Microfilament Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D051966:Phospholipase C gamma; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D016315:Proto-Oncogene Proteins c-abl / Q000378:metabolism; D050737:Proto-Oncogene Proteins c-crk; D051575:Proto-Oncogene Proteins c-yes; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D013329:Structure-Activity Relationship; D010738:Type C Phospholipases / Q000378:metabolism; D018909:src Homology Domains; D019061:src-Family Kinases
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins; D051356:Cortactin; D051380:GRB2 Adaptor Protein; D007527:Isoenzymes; D008024:Ligands; D008840:Microfilament Proteins; D010455:Peptides; D011506:Proteins; D011518:Proto-Oncogene Proteins; D050737:Proto-Oncogene Proteins c-crk; D011993:Recombinant Fusion Proteins; C090468:TP53BP2 protein, human; D016315:Proto-Oncogene Proteins c-abl; D051575:Proto-Oncogene Proteins c-yes; D016392:Proto-Oncogene Proteins pp60(c-src); D019061:src-Family Kinases; D010738:Type C Phospholipases; D051966:Phospholipase C gamma