Chlamydomonas IFT70/CrDYF-1 Is a Core Component of IFT Particle Complex B and Is Required for Flagellar Assembly

Mol Biol Cell. 2010 Aug 1;21(15):2696-706. doi: 10.1091/mbc.e10-03-0191. Epub 2010 Jun 9.


DYF-1 is a highly conserved protein essential for ciliogenesis in several model organisms. In Caenorhabditis elegans, DYF-1 serves as an essential activator for an anterograde motor OSM-3 of intraflagellar transport (IFT), the ciliogenesis-required motility that mediates the transport of flagellar precursors and removal of turnover products. In zebrafish and Tetrahymena DYF-1 influences the cilia tubulin posttranslational modification and may have more ubiquitous function in ciliogenesis than OSM-3. Here we address how DYF-1 biochemically interacts with the IFT machinery by using the model organism Chlamydomonas reinhardtii, in which the anterograde IFT does not depend on OSM-3. Our results show that this protein is a stoichiometric component of the IFT particle complex B and interacts directly with complex B subunit IFT46. In concurrence with the established IFT protein nomenclature, DYF-1 is also named IFT70 after the apparent size of the protein. IFT70/CrDYF-1 is essential for the function of IFT in building the flagellum because the flagella of IFT70/CrDYF-1-depleted cells were greatly shortened. Together, these results demonstrate that IFT70/CrDYF-1 is a canonical subunit of IFT particle complex B and strongly support the hypothesis that the IFT machinery has species- and tissue-specific variations with functional ramifications.

Publication types

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

MeSH terms

  • Algal Proteins / chemistry
  • Algal Proteins / metabolism*
  • Amino Acid Sequence
  • Axoneme / metabolism
  • Axoneme / ultrastructure
  • Chlamydomonas / cytology
  • Chlamydomonas / metabolism*
  • Chlamydomonas / ultrastructure
  • Conserved Sequence / genetics
  • Flagella / metabolism*
  • Flagella / ultrastructure
  • Gene Knockdown Techniques
  • Kinesin / metabolism
  • Molecular Sequence Data
  • Protein Binding
  • Protein Subunits / metabolism
  • Recombinant Proteins / metabolism


  • Algal Proteins
  • Protein Subunits
  • Recombinant Proteins
  • Kinesin