title: Role of kinesin-1 and cytoplasmic dynein in endoplasmic reticulum movement in VERO cells.
abstract: Generating the extended endoplasmic reticulum (ER) network depends on microtubules, which act as tracks for motor-driven ER tubule movement, generate the force to extend ER tubules by means of attachment to growing microtubule plus-ends and provide static attachment points. We have analysed ER dynamics in living VERO cells and find that most ER tubule extension is driven by microtubule motors. Surprisingly, we observe that approximately 50% of rapid ER tubule movements occur in the direction of the centre of the cell, driven by cytoplasmic dynein. Inhibition of this movement leads to an accumulation of lamellar ER in the cell periphery. By expressing dominant-negative kinesin-1 constructs, we show that kinesin-1 drives ER tubule extension towards the cell periphery and that this motility is dependent on the KLC1B kinesin light chain splice form but not on KLC1D. Inhibition of kinesin-1 promotes a shift from tubular to lamellar morphology and slows down the recovery of the ER network after microtubule depolymerisation and regrowth. These observations reconcile previous conflicting studies of kinesin-1 function in ER motility in vivo. Furthermore, our data reveal that cytoplasmic dynein plays a role in ER motility in a mammalian cultured cell, demonstrating that ER motility is more complex than previously thought.
authors.affiliation: Faculty of Life Sciences, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, UK M13 9PT.
authors.forename: Marcin J
authors.initials: MJ
authors.lastname: Woźniak
authors.forename: Becky
authors.initials: B
authors.lastname: Bola
authors.forename: Kim
authors.initials: K
authors.lastname: Brownhill
authors.forename: Yen-Ching
authors.initials: YC
authors.lastname: Yang
authors.forename: Vesselina
authors.initials: V
authors.lastname: Levakova
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Allan
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000378:metabolism; D003595:Cytoplasmic Streaming / Q000502:physiology; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism / Q000502:physiology*; D004721:Endoplasmic Reticulum / Q000502:physiology*; D016547:Kinesins / Q000502:physiology*; D008869:Microtubule-Associated Proteins / Q000378:metabolism / Q000502:physiology; D009068:Movement / Q000502:physiology*; D014709:Vero Cells
chemical_list: D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D004398:Dyneins; D016547:Kinesins