Mechanosignaling between central apparatus and radial spokes controls axonemal dynein activity

Abstract

Nonspecific intermolecular collision between the central pair apparatus and radial spokes underlies a mechanosensing mechanism that regulates dynein activity in Chlamydomonas flagella.

In Situ Localization of N and C Termini of Subunits of the Flagellar Nexin-Dynein Regulatory Complex (N-DRC) Using SNAP Tag and Cryo-electron Tomography

“…Recently, biotin carboxyl carrier protein that can bind biotin covalently has been used successfully to tag and localize axonemal proteins in Chlamydomonas axonemes using cryo-ET (41)(42)(43). Here, we developed a SNAP tag-based labeling approach for cryo-ET studies.…”

The geometric clutch at 20: stripping gears or gaining traction?

“…A most impressive recent study (Oda et al 2014) demonstrated that the loss of motility in central pair projection-deficient mutants of Chlamydomonas can be restored by replacing the missing projection with an unrelated protein of suitable size. These findings on Chlamydomonas suggest that the drc/nexin and the radial spoke-cp interactions may both contribute mechanically to the regulation of inter-doublet spacing, and this may be their essential role in establishing a beat cycle.…”

“…To power a typical 6 mm human epithelial cilium requires w7200 dynein motor proteins. These proteins are arranged in two rows on all but one of the outer doublet microtubules, and at least 15 subtypes of axonemal dynein have been identified in Chlamydomonas flagella, each of which is encoded by a different gene (for reviews, see Hom et al (2011), Kikkawa (2013), Kamiya & Yagi (2014) and Oda et al (2014)). An illustration of a flagellar axoneme in cross-section is shown in Fig.…”

Radial Spokes—A Snapshot of the Motility Regulation, Assembly, and Evolution of Cilia and Flagella

“…For example, in the spoke head, RSP4 and 6 are paralogs expressed from duplicated genes (Curry et al 1992), whereas RSP1 and 10 are homologs with membrane occupation and recognition nexus (MORN) repeats. Analysis of recombinant proteins and tagging indicate that each spoke head contains two copies of each protein that is inherently dimeric (Kohno et al 2011;Oda et al 2014b). Furthermore, the RIIa domains in RSP11 and RSP7, and the Dpy-30 domains in RSP2 and RSP23 (NDK5) in the stalk are dimerization and docking (DD) domains of striking similar tertiary structures .…”