title: DRC3 connects the N-DRC to dynein g to regulate flagellar waveform.
abstract: 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.
authors.affiliation: Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655.
authors.forename: Junya
authors.initials: J
authors.lastname: Awata
authors.affiliation: Biology Department and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454.
authors.forename: Kangkang
authors.initials: K
authors.lastname: Song
authors.affiliation: Biology Department and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Lin
authors.affiliation: Department of Molecular Biology and Biophysics and Institute for Systems Genomics, University of Connecticut Health Center, Farmington, CT 06030.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: King
authors.affiliation: Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01655.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Sanderson
authors.affiliation: Biology Department and Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, MA 02454 nicastro@brandeis.edu george.witman@umassmed.edu.
authors.forename: Daniela
authors.initials: D
authors.lastname: Nicastro
authors.affiliation: Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, MA 01655 nicastro@brandeis.edu george.witman@umassmed.edu.
authors.forename: George B
authors.initials: GB
authors.lastname: Witman
mesh_terms: D056444:Axonemal Dyneins / Q000378:metabolism*; D016825:Chlamydomonas reinhardtii / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020285:Cryoelectron Microscopy; D003599:Cytoskeleton / Q000378:metabolism; D055032:Electron Microscope Tomography; D005407:Flagella / Q000378:metabolism / Q000502:physiology*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship
chemical_list: D008869:Microtubule-Associated Proteins; C484652:microtubule nexin; D056444:Axonemal Dyneins