title: Characterization of diverse internal binding specificities of PDZ domains by yeast two-hybrid screening of a special peptide library.
abstract: Protein-protein interactions (PPIs) are essential events to play important roles in a series of biological processes. There are probably more ways of PPIs than we currently realized. Structural and functional investigations of weak PPIs have lagged behind those of strong PPIs due to technical difficulties. Weak PPIs are often short-lived, which may result in more dynamic signals with important biological roles within and/or between cells. For example, the characteristics of PSD-95/Dlg/ZO-1 (PDZ) domain binding to internal sequences, which are primarily weak interactions, have not yet been systematically explored. In the present study, we constructed a nearly random octapeptide yeast two-hybrid library. A total of 24 PDZ domains were used as baits for screening the library. Fourteen of these domains were able to bind internal PDZ-domain binding motifs (PBMs), and PBMs screened for nine PDZ domains exhibited strong preferences. Among 11 PDZ domains that have not been reported their internal PBM binding ability, six were confirmed to bind internal PBMs. The first PDZ domain of LNX2, which has not been reported to bind C-terminal PBMs, was found to bind internal PBMs. These results suggest that the internal PBMs binding ability of PDZ domains may have been underestimated. The data provided diverse internal binding properties for several PDZ domains that may help identify their novel binding partners.
authors: National Key Laboratory of Medical Molecular Biology, Department of Physiology and Pathophysiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, P.R. China.
authors: Yi
authors: Y
authors: Mu
authors: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China.
authors: Pengfei
authors: P
authors: Cai
authors: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China.
authors: Siqi
authors: S
authors: Hu
authors: National Key Laboratory of Medical Molecular Biology, Department of Physiology and Pathophysiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, P.R. China.
authors: Sucan
authors: S
authors: Ma
authors: National Key Laboratory of Medical Molecular Biology, Department of Physiology and Pathophysiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, P.R. China.
authors: Youhe
authors: Y
authors: Gao
mesh_terms: D000595:Amino Acid Sequence; D006801:Humans; D008969:Molecular Sequence Data; D054731:PDZ Domains / Q000502:physiology*; D019151:Peptide Library; D010455:Peptides / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology*; D054730:Protein Interaction Domains and Motifs / Q000502:physiology*; D011506:Proteins / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D019151:Peptide Library; D010455:Peptides; D011506:Proteins