title: CLIP-170-dependent capture of membrane organelles by microtubules initiates minus-end directed transport.
abstract: Cytoplasmic microtubules (MTs) continuously grow and shorten at free plus ends. During mitosis, this dynamic behavior allows MTs to capture chromosomes to initiate their movement to the spindle poles; however, the role of MT dynamics in capturing organelles for transport in interphase cells has not been demonstrated. Here we use Xenopus melanophores to test the hypothesis that MT dynamics significantly contribute to the efficiency of MT minus-end directed transport of membrane organelles. We demonstrate that initiation of transport of membrane-bounded melanosomes (pigment granules) to the cell center involves their capture by MT plus ends, and that inhibition of MT dynamics or loss of the MT plus-end tracking protein CLIP-170 from MT tips dramatically inhibits pigment aggregation. We conclude that MT dynamics are required for the initiation of MT transport of membrane organelles in interphase cells, and that +TIPs such as CLIP-170 play an important role in this process.
authors.affiliation: Center for Cell Analysis and Modeling and Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06032, USA.
authors.forename: Alexis J
authors.initials: AJ
authors.lastname: Lomakin
authors.forename: Irina
authors.initials: I
authors.lastname: Semenova
authors.forename: Ilya
authors.initials: I
authors.lastname: Zaliapin
authors.forename: Pavel
authors.initials: P
authors.lastname: Kraikivski
authors.forename: Elena
authors.initials: E
authors.lastname: Nadezhdina
authors.forename: Boris M
authors.initials: BM
authors.lastname: Slepchenko
authors.forename: Anna
authors.initials: A
authors.lastname: Akhmanova
authors.forename: Vladimir
authors.initials: V
authors.lastname: Rodionov
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D007700:Kinetics; D008547:Melanophores / Q000378:metabolism*; D020460:Melanosomes / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000379:methods; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D015388:Organelles / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism; D014981:Xenopus
chemical_list: D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D014404:Tubulin; C076744:cytoplasmic linker protein 170