Force balances between interphase centrosomes as revealed by laser ablation

Mol Biol Cell. 2019 Jul 1;30(14):1705-1715. doi: 10.1091/mbc.E19-01-0034. Epub 2019 May 8.

Abstract

Numerous studies have highlighted the self-centering activities of individual microtubule (MT) arrays in animal cells, but relatively few works address the behavior of multiple arrays that coexist in a common cytoplasm. In multinucleated Dictyostelium discoideum cells, each centrosome organizes a radial MT network, and these networks remain separate from one another. This feature offers an opportunity to reveal the mechanism(s) responsible for the positioning of multiple centrosomes. Using a laser microbeam to eliminate one of the two centrosomes in binucleate cells, we show that the unaltered array is rapidly repositioned at the cell center. This result demonstrates that each MT array is constantly subject to centering forces and infers a mechanism to balance the positions of multiple arrays. Our results address the limited actions of three kinesins and a cross-linking MAP that are known to have effects in maintaining MT organization and suggest a simple means used to keep the arrays separated.

Publication types

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

MeSH terms

  • Biomechanical Phenomena
  • Cell Nucleus / metabolism
  • Centrosome / metabolism*
  • Dictyostelium / cytology*
  • Dictyostelium / metabolism*
  • Interphase*
  • Laser Therapy*
  • Microtubule-Associated Proteins / metabolism
  • Microtubules / metabolism
  • Molecular Motor Proteins / metabolism
  • Mutation / genetics
  • Protozoan Proteins / metabolism

Substances

  • Microtubule-Associated Proteins
  • Molecular Motor Proteins
  • Protozoan Proteins