title: Mapping and characterization of the interaction interface between two polypyrimidine-tract binding proteins and a nova-type protein of Solanum tuberosum.
abstract: Polypyrimidine tract-binding (PTB) proteins are RNA-binding proteins that generally contain four RNA recognition motifs (RRMs). In potato, six cDNAs encoding full-length PTB proteins have been identified. In the present study Nova1-like protein, designated StNova1, was identified as a potential interacting partner of the StPTB proteins via yeast two-hybrid screening. Nova protein is a RNA-binding protein that contains three K-homology (KH) domains. In humans, these proteins are involved in regulation of neuronal RNA metabolism but the role of Nova-like proteins in plants is poorly understood. We have validated this interaction and mapped the protein binding region on StNova1 and StPTB1 and -6 using a novel domain interaction phage display (DIPP) technique. The interaction between the two RNA-binding proteins StPTB1/6 and StNova1 is mediated through linker regions that are distinctly separated from the RRMs. Furthermore, using a random 21-mer phage-peptide library, we have identified a number of peptides with the consensus sequence motif [S/G][V/I][L/V]G that recognize the StPTB proteins. One over-represented peptide that recognizes StPTB6 contains the GVLGPWP sequence that is similar to the GIGGRYP sequence in the glycine-rich linker region between the KH2 and KH3 domains of StNova1. We show, through site-specific mutations, the importance of glycine and proline residues in StNova1-StPTB interactions.
authors.affiliation: Roy J. Carver Department of Biochemistry Biophysics and Molecular Biology, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Shweta
authors.initials: S
authors.lastname: Shah
authors.forename: Nathaniel M
authors.initials: NM
authors.lastname: Butler
authors.forename: David J
authors.initials: DJ
authors.lastname: Hannapel
authors.forename: A Gururaj
authors.initials: AG
authors.lastname: Rao
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000951:Antigens, Neoplasm / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001665:Binding Sites; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D061505:Cell Surface Display Techniques; D008969:Molecular Sequence Data; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000090682:Neuro-Oncological Ventral Antigen; D019151:Peptide Library; D038941:Polypyrimidine Tract-Binding Protein / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D016415:Sequence Alignment; D011198:Solanum tuberosum / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000951:Antigens, Neoplasm; D002352:Carrier Proteins; D009419:Nerve Tissue Proteins; D000090682:Neuro-Oncological Ventral Antigen; D019151:Peptide Library; D016601:RNA-Binding Proteins; D038941:Polypyrimidine Tract-Binding Protein