Kinesin I and cytoplasmic dynein orchestrate glucose-stimulated insulin-containing vesicle movements in clonal MIN6 beta-cells

Biochem Biophys Res Commun. 2003 Nov 14;311(2):272-82. doi: 10.1016/j.bbrc.2003.09.208.

Abstract

Glucose-stimulated mobilization of large dense-core vesicles (LDCVs) to the plasma membrane is essential for sustained insulin secretion. At present, the cytoskeletal structures and molecular motors involved in vesicle trafficking in beta-cells are poorly defined. Here, we describe simultaneous imaging of enhanced green fluorescent protein (EGFP)-tagged LDCVs and microtubules in beta-cells. Microtubules exist as a tangled array, along which vesicles describe complex directional movements. Whilst LDCVs frequently changed direction, implying the involvement of both plus- and minus-end directed motors, inactivation of the minus-end motor, cytoplasmic dynein, inhibited only a small fraction of all vesicle movements which were involved in vesicle recovery after glucose-stimulated exocytosis. By contrast, selective silencing of the plus-end motor, kinesin I, with small interfering RNAs substantially inhibited all vesicle movements. We conclude that the majority of LDCV transport in beta-cells is mediated by kinesin I, whilst dynein probably contributes to the recovery of vesicles after rapid kiss-and-run exocytosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport, Active / physiology
  • Cell Line
  • Cell Movement / physiology*
  • Clone Cells
  • Cytoplasm / metabolism
  • Dyneins / physiology*
  • Glucose / metabolism*
  • HeLa Cells
  • Humans
  • Insulin / metabolism*
  • Islets of Langerhans / cytology
  • Islets of Langerhans / physiology*
  • Kinesin / physiology*
  • Microtubules / physiology*
  • Microtubules / ultrastructure
  • Molecular Motor Proteins / physiology*
  • Secretory Vesicles / physiology*
  • Secretory Vesicles / ultrastructure

Substances

  • Insulin
  • Molecular Motor Proteins
  • Dyneins
  • Kinesin
  • Glucose