Ciliary proteins Fap43 and Fap44 interact with each other and are essential for proper cilia and flagella beating

Cell Mol Life Sci. 2018 Dec;75(24):4479-4493. doi: 10.1007/s00018-018-2819-7. Epub 2018 Apr 23.


Cilia beating is powered by the inner and outer dynein arms (IDAs and ODAs). These multi-subunit macrocomplexes are arranged in two rows on each outer doublet along the entire cilium length, except its distal end. To generate cilia beating, the activity of ODAs and IDAs must be strictly regulated locally by interactions with the dynein arm-associated structures within each ciliary unit and coordinated globally in time and space between doublets and along the axoneme. Here, we provide evidence of a novel ciliary complex composed of two conserved WD-repeat proteins, Fap43p and Fap44p. This complex is adjacent to another WD-repeat protein, Fap57p, and most likely the two-headed inner dynein arm, IDA I1. Loss of either protein results in altered waveform, beat stroke and reduced swimming speed. The ciliary localization of Fap43p and Fap44p is interdependent in the ciliate Tetrahymena thermophila.

Keywords: Dyh6; Dyh7; Tether/tether head complex; Wdr52; Wdr65; Wdr96.

MeSH terms

  • Chlamydomonas / genetics
  • Chlamydomonas / metabolism*
  • Cilia / genetics
  • Cilia / metabolism
  • Flagella / genetics
  • Flagella / metabolism*
  • Gene Deletion
  • Gene Knockout Techniques
  • Humans
  • Mutation
  • Phylogeny
  • Plant Proteins / analysis
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Protein Interaction Maps
  • Protozoan Proteins / analysis
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism*
  • Tetrahymena / genetics
  • Tetrahymena / metabolism*
  • WD40 Repeats


  • Plant Proteins
  • Protozoan Proteins