title: C-terminal recognition by 14-3-3 proteins for surface expression of membrane receptors.
abstract: Diverse functions of 14-3-3 proteins are directly coupled to their ability to interact with targeted peptide substrates. RSX(pS/pT)XP and RXPhiX(pS/pT)XP are two canonical consensus binding motifs for 14-3-3 proteins representing the two common binding modes, modes I and II, between 14-3-3 and internal peptides. Using a genetic selection, we have screened a random peptide library and identified a group of C-terminal motifs, termed SWTY, capable of overriding an endoplasmic reticulum localization signal and redirecting membrane proteins to cell surface. Here we report that the C-terminal SWTY motif, although different from mode I and II consensus, binds tightly to 14-3-3 proteins with a dissociation constant (K(D)) of 0.17 microM, comparable with that of internal canonical binding peptides. We show that all residues but proline in -SWTX-COOH are compatible for the interaction and surface expression. Because SWTY-like sequences have been found in native proteins, these results support a broad significance of 14-3-3 interaction with protein C termini. The C-terminal binding consensus, mode III, represents an expansion of the repertoire of 14-3-3-targeted sequences.
authors.affiliation: Department of Neuroscience and High Throughput Biology Center, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Coblitz
authors.forename: Sojin
authors.initials: S
authors.lastname: Shikano
authors.forename: Meng
authors.initials: M
authors.lastname: Wu
authors.forename: Sandra B
authors.initials: SB
authors.lastname: Gabelli
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Cockrell
authors.forename: Matt
authors.initials: M
authors.lastname: Spieker
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Hanyu
authors.forename: Haian
authors.initials: H
authors.lastname: Fu
authors.forename: L Mario
authors.initials: LM
authors.lastname: Amzel
authors.forename: Min
authors.initials: M
authors.lastname: Li
mesh_terms: D048948:14-3-3 Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D016880:Anisotropy; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005434:Flow Cytometry; D015723:Gene Library; D005822:Genetic Vectors; D006801:Humans; D015151:Immunoblotting; D007700:Kinetics; D051379:Mice; D008956:Models, Chemical; D008969:Molecular Sequence Data; D009154:Mutation; D010455:Peptides / Q000737:chemistry; D024661:Potassium Channels, Inwardly Rectifying / Q000378:metabolism; D011392:Proline / Q000737:chemistry; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D048948:14-3-3 Proteins; C489461:Kir2.1 channel; D010455:Peptides; D024661:Potassium Channels, Inwardly Rectifying; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D011392:Proline