The centrosomal linker and microtubules provide dual levels of spatial coordination of centrosomes

PLoS Genet. 2015 May 22;11(5):e1005243. doi: 10.1371/journal.pgen.1005243. eCollection 2015 May.

Abstract

The centrosome is the principal microtubule organizing center in most animal cells. It consists of a pair of centrioles surrounded by pericentriolar material. The centrosome, like DNA, duplicates exactly once per cell cycle. During interphase duplicated centrosomes remain closely linked by a proteinaceous linker. This centrosomal linker is composed of rootletin filaments that are anchored to the centrioles via the protein C-Nap1. At the onset of mitosis the linker is dissolved by Nek2A kinase to support the formation of the bipolar mitotic spindle. The importance of the centrosomal linker for cell function during interphase awaits characterization. Here we assessed the phenotype of human RPE1 C-Nap1 knockout (KO) cells. The absence of the linker led to a modest increase in the average centrosome separation from 1 to 2.5 μm. This small impact on the degree of separation is indicative of a second level of spatial organization of centrosomes. Microtubule depolymerisation or stabilization in C-Nap1 KO cells dramatically increased the inter-centrosomal separation (> 8 μm). Thus, microtubules position centrosomes relatively close to one another in the absence of linker function. C-Nap1 KO cells had a Golgi organization defect with a two-fold expansion of the area occupied by the Golgi. When the centrosomes of C-Nap1 KO cells showed considerable separation, two spatially distinct Golgi stacks could be observed. Furthermore, migration of C-Nap1 KO cells was slower than their wild type RPE1 counterparts. These data show that the spatial organization of centrosomes is modulated by a combination of centrosomal cohesion and microtubule forces. Furthermore a modest increase in centrosome separation has major impact on Golgi organization and cell migration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autoantigens / genetics
  • Autoantigens / metabolism
  • Cell Cycle
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cell Line, Tumor
  • Cell Movement
  • Centrosome / metabolism*
  • HeLa Cells
  • Humans
  • Interphase
  • Microscopy, Electron, Transmission
  • Microtubules / genetics*
  • Microtubules / metabolism
  • Mitosis
  • NIMA-Related Kinases
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism
  • Spindle Apparatus / genetics

Substances

  • Autoantigens
  • Cell Cycle Proteins
  • Cep250 protein, human
  • NEK2 protein, human
  • NIMA-Related Kinases
  • Protein-Serine-Threonine Kinases

Grant support

MP is a fellow of Hartmut Hoffmann-Berling International Graduate School of Molecular and Cellular Biology (HBIGS). SH is a research fellow of Japan Society for the Promotion of Science. SH is supported by the Naito foundation. The work of ES is supported by funds from the Deutsches Krebsforschung Zentrum-Zentrum für Molekulare Biologie Allianz. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.