title: The scaffolding protein CASK mediates the interaction between rabphilin3a and beta-neurexins.
abstract: CASK, a member of the membrane-associated guanylate kinase (MAGUK) superfamily, binds to the carboxyl-terminus of beta-neurexins on the intracellular side of the presynaptic membrane. The guanylate kinase-like (GUK) domains of MAGUKs lack kinase activities, but might be important for mediating specific protein-protein interaction. By a yeast two-hybrid approach, we identified an interaction between the GUK domain of CASK and the C2B domain of rabphilin3a, a presynaptic protein involved in synaptic vesicle exocytosis. The interaction was confirmed by in vitro GST pull-down and co-immunoprecipitation assays. It was proposed that presynaptic vesicles might be guided to the vicinity of points of exocytosis defined by beta-neurexins via the interaction between rabphilin3a-CASK-beta-neurexins.
authors.affiliation: Max-Planck Guest Laboratory, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, 320, Yue-Yang Road, 200031, Shanghai, PR China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: Z
authors.initials: Z
authors.lastname: Luan
authors.forename: A
authors.initials: A
authors.lastname: Liu
authors.forename: G
authors.initials: G
authors.lastname: Hu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D005089:Exocytosis; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D051528:Guanylate Kinases; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009703:Nucleoside-Phosphate Kinase / Q000378:metabolism* / Q000494:pharmacology; D011233:Precipitin Tests; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D020033:Protein Isoforms / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013572:Synaptic Vesicles / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D033921:Vesicular Transport Proteins; D020691:rab GTP-Binding Proteins / Q000378:metabolism*; D000097624:Rabphilin-3A
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D005982:Glutathione Transferase; D051528:Guanylate Kinases; D009419:Nerve Tissue Proteins; D009703:Nucleoside-Phosphate Kinase; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D033921:Vesicular Transport Proteins; D020691:rab GTP-Binding Proteins; D000097624:Rabphilin-3A; C093175:neurexin II; C086958:neurexin IIIbeta; C086959:neurexin Ibeta; C106868:CASK kinases