Golgi Outposts Shape Dendrite Morphology by Functioning as Sites of Acentrosomal Microtubule Nucleation in Neurons

Neuron. 2012 Dec 6;76(5):921-30. doi: 10.1016/j.neuron.2012.10.008.

Abstract

Microtubule nucleation is essential for proper establishment and maintenance of axons and dendrites. Centrosomes, the primary site of nucleation in most cells, lose their function as microtubule organizing centers during neuronal development. How neurons generate acentrosomal microtubules remains unclear. Drosophila dendritic arborization (da) neurons lack centrosomes and therefore provide a model system to study acentrosomal microtubule nucleation. Here, we investigate the origin of microtubules within the elaborate dendritic arbor of class IV da neurons. Using a combination of in vivo and in vitro techniques, we find that Golgi outposts can directly nucleate microtubules throughout the arbor. This acentrosomal nucleation requires gamma-tubulin and CP309, the Drosophila homolog of AKAP450, and contributes to the complex microtubule organization within the arbor and dendrite branch growth and stability. Together, these results identify a direct mechanism for acentrosomal microtubule nucleation within neurons and reveal a function for Golgi outposts in this process.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • A Kinase Anchor Proteins / genetics
  • A Kinase Anchor Proteins / metabolism
  • Animals
  • Animals, Genetically Modified
  • Dendrites / ultrastructure
  • Drosophila
  • Drosophila Proteins / genetics
  • Golgi Apparatus / metabolism*
  • Golgi Apparatus / ultrastructure
  • Green Fluorescent Proteins / genetics
  • Microtubule-Organizing Center / metabolism*
  • Microtubule-Organizing Center / ultrastructure
  • Microtubules / metabolism*
  • Neurons / metabolism*
  • Neurons / ultrastructure*

Substances

  • A Kinase Anchor Proteins
  • Drosophila Proteins
  • Green Fluorescent Proteins