NIMA-related kinase TbNRKC is involved in basal body separation in Trypanosoma brucei

J Cell Sci. 2006 May 1;119(Pt 9):1852-63. doi: 10.1242/jcs.02900. Epub 2006 Apr 11.

Abstract

The NIMA-related kinase 2 (NEK 2) has important cell cycle functions related to centriole integrity and splitting. Trypanosoma brucei does not possess centrioles, however, cytokinesis is coupled to basal body separation events. Here we report the first functional characterisation of a T. brucei basal body-cytoskeletal NIMA-related kinase (NRK) protein, TbNRKC. The TbNRKC kinase domain has high amino acid identity with the human NEK1 kinase domain (50%) but also shares 42% identity with human NEK2. TbNRKC is expressed in bloodstream and procyclic cells and functions as a bona fide kinase in vitro. Remarkably, RNAi knockdown of TbNRKC and overexpression of kinase-dead TbNRKC in procyclic forms induces the accumulation of cells with four basal bodies, whereas overexpression of active protein produces supernumary basal bodies and blocks cytokinesis. TbNRKC is located on mature and immature basal bodies and is the first T. brucei NRK to be found associated with the basal body cytokinesis pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Division / physiology*
  • Flagella / metabolism
  • Flagella / ultrastructure*
  • Humans
  • Molecular Sequence Data
  • NIMA-Related Kinase 1
  • Phenotype
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism*
  • RNA Interference
  • Sequence Alignment
  • Trypanosoma brucei brucei* / cytology
  • Trypanosoma brucei brucei* / enzymology

Substances

  • Cell Cycle Proteins
  • Protozoan Proteins
  • NEK1 protein, human
  • NIMA-Related Kinase 1
  • Protein Serine-Threonine Kinases