Par6γ is at the mother centriole and controls centrosomal protein composition through a Par6α-dependent pathway

J Cell Sci. 2013 Feb 1;126(Pt 3):860-70. doi: 10.1242/jcs.121186. Epub 2012 Dec 21.

Abstract

The centrosome contains two centrioles that differ in age, protein composition and function. This non-membrane bound organelle is known to regulate microtubule organization in dividing cells and ciliogenesis in quiescent cells. These specific roles depend on protein appendages at the older, or mother, centriole. In this study, we identified the polarity protein partitioning defective 6 homolog gamma (Par6γ) as a novel component of the mother centriole. This specific localization required the Par6γ C-terminus, but was independent of intact microtubules, the dynein/dynactin complex and the components of the PAR polarity complex. Par6γ depletion resulted in altered centrosomal protein composition, with the loss of a large number of proteins, including Par6α and p150(Glued), from the centrosome. As a consequence, there were defects in ciliogenesis, microtubule organization and centrosome reorientation during migration. Par6γ interacted with Par3 and aPKC, but these proteins were not required for the regulation of centrosomal protein composition. Par6γ also associated with Par6α, which controls protein recruitment to the centrosome through p150(Glued). Our study is the first to identify Par6γ as a component of the mother centriole and to report a role of a mother centriole protein in the regulation of centrosomal protein composition.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Amino Acid Sequence
  • Cell Division
  • Cell Polarity*
  • Centrioles / metabolism*
  • Centrosome / metabolism*
  • Dynactin Complex
  • Dyneins / metabolism
  • HeLa Cells
  • Humans
  • Intercellular Junctions
  • Microtubule-Associated Proteins / metabolism
  • Microtubules / metabolism
  • Molecular Sequence Data
  • Multiprotein Complexes / metabolism*
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • RNA, Small Interfering / genetics
  • Signal Transduction

Substances

  • Adaptor Proteins, Signal Transducing
  • DCTN1 protein, human
  • Dynactin Complex
  • Microtubule-Associated Proteins
  • Multiprotein Complexes
  • PARD6A protein, human
  • Protein Isoforms
  • RNA, Small Interfering
  • Dyneins