Modulation of phosphatidylinositol 4-phosphate levels by CaBP7 controls cytokinesis in mammalian cells

Mol Biol Cell. 2015 Apr 15;26(8):1428-39. doi: 10.1091/mbc.E14-07-1243. Epub 2015 Feb 25.

Abstract

Calcium and phosphoinositide signaling regulate cell division in model systems, but their significance in mammalian cells is unclear. Calcium-binding protein-7 (CaBP7) is a phosphatidylinositol 4-kinaseIIIβ (PI4KIIIβ) inhibitor required during cytokinesis in mammalian cells, hinting at a link between these pathways. Here we characterize a novel association of CaBP7 with lysosomes that cluster at the intercellular bridge during cytokinesis in HeLa cells. We show that CaBP7 regulates lysosome clustering and that PI4KIIIβ is essential for normal cytokinesis. CaBP7 depletion induces lysosome mislocalization, extension of intercellular bridge lifetime, and cytokinesis failure. These data connect phosphoinositide and calcium pathways to lysosome localization and normal cytokinesis in mammalian cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium-Binding Proteins / physiology*
  • Cytokinesis / physiology*
  • HeLa Cells
  • Humans
  • Lysosomes / physiology*
  • Phosphatidylinositol Phosphates / metabolism*
  • Signal Transduction

Substances

  • CABP7 protein, human
  • Calcium-Binding Proteins
  • Phosphatidylinositol Phosphates
  • phosphatidylinositol 4-phosphate