title: Interaction with a kinesin-2 tail propels choline acetyltransferase flow towards synapse.
abstract: Bulk flow constitutes a substantial part of the slow transport of soluble proteins in axons. Though the underlying mechanism is unclear, evidences indicate that intermittent, kinesin-based movement of large protein-aggregates aids this process. Choline acetyltransferase (ChAT), a soluble enzyme catalyzing acetylcholine synthesis, propagates toward the synapse at an intermediate, slow rate. The presynaptic enrichment of ChAT requires heterotrimeric kinesin-2, comprising KLP64D, KLP68D and DmKAP, in Drosophila. Here, we show that the bulk flow of a recombinant Green Fluorescent Protein-tagged ChAT (GFP::ChAT), in Drosophila axons, lacks particulate features. It occurs for a brief period during the larval stages. In addition, both the endogenous ChAT and GFP::ChAT directly bind to the KLP64D tail, which is essential for the GFP::ChAT entry and anterograde flow in axon. These evidences suggest that a direct interaction with motor proteins could regulate the bulk flow of soluble proteins, and thus establish their asymmetric distribution.
authors.affiliation: Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India.
authors.forename: Aparna
authors.initials: A
authors.lastname: Sadananda
authors.forename: Runa
authors.initials: R
authors.lastname: Hamid
authors.forename: Harinath
authors.initials: H
authors.lastname: Doodhi
authors.forename: Debnath
authors.initials: D
authors.lastname: Ghosal
authors.forename: Mukul
authors.initials: M
authors.lastname: Girotra
authors.forename: Swadhin Chandra
authors.initials: SC
authors.lastname: Jana
authors.forename: Krishanu
authors.initials: K
authors.lastname: Ray
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001370:Axonal Transport / Q000235:genetics / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D059329:Cholinergic Neurons / Q000201:enzymology / Q000378:metabolism; D004330:Drosophila / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000737:chemistry / Q000378:metabolism*; D036681:Fluorescence Recovery After Photobleaching; D016547:Kinesins / Q000737:chemistry / Q000378:metabolism*; D007814:Larva / Q000201:enzymology / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D013569:Synapses / Q000201:enzymology / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D029721:Drosophila Proteins; C486144:Kap3 protein, Drosophila; D008869:Microtubule-Associated Proteins; D002795:Choline O-Acetyltransferase; C525729:kinesin 2 protein, Drosophila; D016547:Kinesins