EMD-6754

Subtomogram averaging
50.0 Å
EMD-6754 Deposition: 12/06/2017
Map released: 12/07/2017
Last modified: 20/06/2018
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-6754

Electrostatic interaction between polyglutamylated tubulin and the nexin-dynein regulatory complex regulates flagellar motility

EMD-6754

Subtomogram averaging
50.0 Å
EMD-6754 Deposition: 12/06/2017
Map released: 12/07/2017
Last modified: 20/06/2018
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Chlamydomonas reinhardtii
Sample: Outer doublet microtubule of pf2fp3 axoneme labeled with polyE2 Fab fragments

Deposition Authors: Kubo T, Oda T
Electrostatic interaction between polyglutamylated tubulin and the nexin-dynein regulatory complex regulates flagellar motility.
Kubo T, Oda T
(2017) Mol. Biol. Cell , 28 , 2260 - 2266
PUBMED: 28637765
DOI: doi:10.1091/mbc.E17-05-0285
ISSN: 1939-4586
Abstract:
Tubulins undergo various posttranslational modifications. Among them, polyglutamylation is involved in the motility of eukaryotic flagella and the stability of the axonemal microtubules. However, it remains unclear where polyglutamylated tubulin localizes precisely within the axoneme and how tubulin polyglutamylation affects flagellar motility. In this study, we identified the three-dimensional localization of the polyglutamylated tubulin in Chlamydomonas flagella using antibody labeling and cryo-electron tomography. Polyglutamylated tubulins specifically located in close proximity to a microtubule-cross-bridging structure called the nexin-dynein regulatory complex (N-DRC). Because N-DRC is positively charged, we hypothesized that there is an electrostatic interaction between the polyglutamylated tubulin and the N-DRC, and therefore we mutated the amino acid sequences of DRC4 to modify the charge of the N-DRC. We found that both augmentation and reduction of the positive charge on DRC4 resulted in reduced flagellar motility. Moreover, reduced motility in a mutant with a structurally defective N-DRC was partially restored by increasing the positive charge on DRC4. These results clearly indicate that beating motion of flagella is maintained by the electrostatic cross-bridge formed between the negatively charged polyglutamylated tubulins and the positively charged N-DRC.