title: Cargo selection by specific kinesin light chain 1 isoforms.
abstract: Kinesin-1 drives the movement of diverse cargoes, and it has been proposed that specific kinesin light chain (KLC) isoforms target kinesin-1 to these different structures. Here, we test this hypothesis using two in vitro motility assays, which reconstitute the movement of rough endoplasmic reticulum (RER) and vesicles present in a Golgi membrane fraction. We generated GST-tagged fusion proteins of KLC1B and KLC1D that included the tetratricopeptide repeat domain and the variable C-terminus. We find that preincubation of RER with KLC1B inhibits RER motility, whereas KLC1D does not. In contrast, Golgi fraction vesicle movement is inhibited by KLC1D but not KLC1B reagents. Both RER and vesicle movement is inhibited by preincubation with the GST-tagged C-terminal domain of ubiquitous kinesin heavy chain (uKHC), which binds to the N-terminal domain of uKHC and alters its interaction with microtubules. We propose that although the TRR domains are required for cargo binding, it is the variable C-terminal region of KLCs that are vital for targeting kinesin-1 to different cellular structures.
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester, UK.
authors.forename: Marcin J
authors.initials: MJ
authors.lastname: Woźniak
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Allan
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001681:Biological Assay; D022162:Cytoplasmic Vesicles / Q000187:drug effects; D004721:Endoplasmic Reticulum / Q000187:drug effects*; D006056:Golgi Apparatus / Q000737:chemistry / Q000187:drug effects* / Q000648:ultrastructure; D007425:Intracellular Membranes / Q000187:drug effects; D016547:Kinesins; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000235:genetics / Q000494:pharmacology*; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000032:analysis / Q000235:genetics / Q000494:pharmacology; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000494:pharmacology
chemical_list: C000715690:Klc1 protein, rat; D008869:Microtubule-Associated Proteins; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D016547:Kinesins