Drosophila Ensconsin Promotes Productive Recruitment of Kinesin-1 to Microtubules

Dev Cell. 2008 Dec;15(6):866-76. doi: 10.1016/j.devcel.2008.10.006.

Abstract

Ensconsin is a conserved microtubule-associated protein (MAP) that interacts dynamically with microtubules, but its cellular function has remained elusive. We show that Drosophila ensconsin is required for all known kinesin-1-dependent processes in the polarized oocyte without detectable effects on microtubules. ensconsin is also required in neurons. Using a single molecule assay for kinesin-1 motility in Drosophila ovary extract, we show that recruitment to microtubules and subsequent motility is severely impaired without ensconsin. Ensconsin protein is enriched at the oocyte anterior and apically in polarized epithelial cells, although required for localization of posterior determinants. Par-1 is required for ensconsin localization and directly phosphorylates it at conserved sites. Our results reveal an unexpected function of a MAP, promoting productive recruitment of a specific motor to microtubules, and an additional level of kinesin regulation. Furthermore, spatial control of motor recruitment can provide additional regulatory control in Par-1 and microtubule-dependent cell polarity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Movement
  • Cell Polarity
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / metabolism*
  • Female
  • Gene Expression Regulation, Developmental*
  • Glycogen Synthase Kinase 3
  • Green Fluorescent Proteins / metabolism
  • Kinesin / metabolism*
  • Microtubule-Associated Proteins / metabolism
  • Microtubule-Associated Proteins / physiology*
  • Microtubules / metabolism*
  • Models, Biological
  • Neurons / metabolism
  • Oocytes / metabolism
  • Ovary / metabolism
  • Protein-Serine-Threonine Kinases / metabolism

Substances

  • Drosophila Proteins
  • Microtubule-Associated Proteins
  • epithelial microtubule-associate protein, 115 kDa
  • Green Fluorescent Proteins
  • Protein-Serine-Threonine Kinases
  • Glycogen Synthase Kinase 3
  • Par-1 protein, Drosophila
  • Kinesin