title: GRIF-1-kinesin-1 interactions: a confocal microscopy study.
abstract: GRIF-1 [GABA(A) (gamma-aminobutyric acid(A)) receptor interacting factor-1] is a member of a coiled-coil family of proteins thought to function as adaptors in the anterograde trafficking of organelles utilizing the kinesin-1 motor proteins to synapses. To study in more detail the molecular interaction between GRIF-1 and the kinesin-1 family member KIF5C, fluorescent yellow- and fluorescent cyan-tagged GRIF-1, KIF5C, the KIF5C MD (motor domain) and the KIF5C NMD (non-motor domain) fusion proteins were generated. Each was characterized with respect to size and ability to co-associate by immunoprecipitation following expression in HEK-293 (human embryonic kidney 293) cells. Further, their distribution in transfected HEK-293 and transformed African green monkey kidney (COS-7) cells was analysed by confocal microscopy. The fluorescent GRIF-1 and KIF5C fusion proteins were all found to behave as wild-type. Double GRIF-1/KIF5C transfectants revealed co-localization. The GRIF-1/KIF5C and GRIF-1/KIF5C NMD double transfectants showed different subcellular distributions compared with single GRIF-1, KIF5C or KIF5C NMD transfections. These studies confirm the association between GRIF-1 and kinesin-1 NMDs. Fluorescence resonance energy transfer studies are ongoing to characterize this interaction in more detail.
authors.affiliation: School of Pharmacy, University of London, 29/39 Brunswick Square, London WC1N 1AX, UK.
authors.forename: K
authors.initials: K
authors.lastname: Pozo
authors.forename: F A
authors.initials: FA
authors.lastname: Stephenson
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002522:Chlorocebus aethiops; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D016547:Kinesins / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; C465341:TRAK2 protein, human; D016547:Kinesins