title: Coordinated transport of phosphorylated amyloid-beta precursor protein and c-Jun NH2-terminal kinase-interacting protein-1.
abstract: The transmembrane protein amyloid-beta precursor protein (APP) and the vesicle-associated protein c-Jun NH(2)-terminal kinase-interacting protein-1 (JIP-1) are transported into axons by kinesin-1. Both proteins may bind to kinesin-1 directly and can be transported separately. Because JIP-1 and APP can interact, kinesin-1 may recruit them as a complex, enabling their cotransport. In this study, we tested whether APP and JIP-1 are transported together or separately on different vesicles. We found that, within the cellular context, JIP-1 preferentially interacts with Thr(668)-phosphorylated APP (pAPP), compared with nonphosphorylated APP. In neurons, JIP-1 colocalizes with vesicles containing pAPP and is excluded from those containing nonphosphorylated APP. The accumulation of JIP-1 and pAPP in neurites requires kinesin-1, and the expression of a phosphomimetic APP mutant increases JIP-1 transport. Down-regulation of JIP-1 by small interfering RNA specifically impairs transport of pAPP, with no effect on the trafficking of nonphosphorylated APP. These results indicate that the phosphorylation of APP regulates the formation of a pAPP-JIP-1 complex that accumulates in neurites independent of nonphosphorylated APP.
authors.affiliation: Department of Physiology and Biophysics, Case School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA. zoia.muresan@case.edu
authors.forename: Zoia
authors.initials: Z
authors.lastname: Muresan
authors.forename: Virgil
authors.initials: V
authors.lastname: Muresan
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D001369:Axons / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D001692:Biological Transport; D019921:Biotinylation; D015153:Blotting, Western; D001921:Brain / Q000473:pathology; D019556:COS Cells; D002460:Cell Line; D002465:Cell Movement; D002522:Chlorocebus aethiops; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D016547:Kinesins / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence; D009154:Mutation; D016501:Neurites / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D016564:Amyloid beta-Protein Precursor; D001426:Bacterial Proteins; D008164:Luminescent Proteins; C490666:MAPK8IP1 protein, human; C490665:Mapk8ip protein, mouse; D034741:RNA, Small Interfering; C054562:yellow fluorescent protein, Bacteria; D016547:Kinesins