DRC3 connects the N-DRC to dynein g to regulate flagellar waveform

Mol Biol Cell. 2015 Aug 1;26(15):2788-800. doi: 10.1091/mbc.E15-01-0018. Epub 2015 Jun 10.


The nexin-dynein regulatory complex (N-DRC), which is a major hub for the control of flagellar motility, contains at least 11 different subunits. A major challenge is to determine the location and function of each of these subunits within the N-DRC. We characterized a Chlamydomonas mutant defective in the N-DRC subunit DRC3. Of the known N-DRC subunits, the drc3 mutant is missing only DRC3. Like other N-DRC mutants, the drc3 mutant has a defect in flagellar motility. However, in contrast to other mutations affecting the N-DRC, drc3 does not suppress flagellar paralysis caused by loss of radial spokes. Cryo-electron tomography revealed that the drc3 mutant lacks a portion of the N-DRC linker domain, including the L1 protrusion, part of the distal lobe, and the connection between these two structures, thus localizing DRC3 to this part of the N-DRC. This and additional considerations enable us to assign DRC3 to the L1 protrusion. Because the L1 protrusion is the only non-dynein structure in contact with the dynein g motor domain in wild-type axonemes and this is the only N-DRC-dynein connection missing in the drc3 mutant, we conclude that DRC3 interacts with dynein g to regulate flagellar waveform.

Publication types

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

MeSH terms

  • Axonemal Dyneins / metabolism*
  • Chlamydomonas reinhardtii / genetics
  • Chlamydomonas reinhardtii / metabolism
  • Chlamydomonas reinhardtii / physiology*
  • Cryoelectron Microscopy
  • Cytoskeleton / metabolism
  • Electron Microscope Tomography
  • Flagella / metabolism
  • Flagella / physiology*
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Microtubules / metabolism
  • Protein Structure, Tertiary
  • Structure-Activity Relationship


  • Microtubule-Associated Proteins
  • microtubule nexin
  • Axonemal Dyneins