@article{8a88b493fd4b4047a882810beb79a8ee,
title = "Structural organization of the intermediate and light chain complex of Chlamydomonas ciliary I1 dynein",
abstract = "Axonemal I1 dynein (dynein f) is the largest inner dynein arm in cilia and a key regulator of ciliary beating. It consists of two dynein heavy chains, and an intermediate chain/light chain (ICLC) complex. However, the structural organization of the nine ICLC subunits remains largely unknown. Here, we used biochemical and genetic approaches, and cryo-electron tomography imaging in Chlamydomonas to dissect the molecular architecture of the I1 dynein ICLC complex. Using a strain expressing SNAP-tagged IC140, tomography revealed the location of the IC140 N-terminus at the proximal apex of the ICLC structure. Mass spectrometry of a tctex2b mutant showed that TCTEX2B dynein light chain is required for the stable assembly of TCTEX1 and inner dynein arm interacting proteins IC97 and FAP120. The structural defects observed in tctex2b located these 4 subunits in the center and bottom regions of the ICLC structure, which overlaps with the location of the IC138 regulatory subcomplex, which contains IC138, IC97, FAP120, and LC7b. These results reveal the three-dimensional organization of the native ICLC complex and indicate potential protein-protein interactions that are involved in the pathway by which I1 regulates ciliary motility.",
keywords = "IC140, ICLC complex, TCTEX2B, cryo-electron tomography, flagella",
author = "Gang Fu and Chasity Scarbrough and Kangkang Song and Nhan Phan and Maureen Wirschell and Daniela Nicastro",
note = "Funding Information: We would like to thank Winfield S. Sale (Emory University) for generously providing antibodies against IC138, CK1, PP2A B subunit and the IC140-GFP-AphVIII plasmid. We also thank Chen Xu (Brandeis University) and Daniel Stoddard (UT Southwestern Medical Center) for management of the electron microscope facilities and training. We appreciate Erin Dymek and Elizabeth Smith for providing the pf16D2 and pf16D2;PF16 strains and their critical discussion on the manuscript. We thank the proteomics core facility at UT Southwestern Medical Center for LC-MS/MS analysis. This work was supported by the National Institutes of Health (NIH) [grant numbers: R01GM083122 to DN, and 5R01GM051173; Emory University Subaward T735204 to M.W] and the Cancer Prevention and Research Institute of Texas (CPRIT) [grant numbers: RR140082 to DN]. The UT Southwestern Cryo-Electron Microscopy Facility is supported in part by the CPRIT Core Facility Support Award RP170644. This research was supported in part by the computational resources provided by the BioHPC supercomputing facility located in the Lyda Hill Department of Bioinformatics, UT Southwestern Medical Center. Funding Information: We would like to thank Winfield S. Sale (Emory University) for generously providing antibodies against IC138, CK1, PP2A B subunit and the IC140‐GFP‐AphVIII plasmid. We also thank Chen Xu (Brandeis University) and Daniel Stoddard (UT Southwestern Medical Center) for management of the electron microscope facilities and training. We appreciate Erin Dymek and Elizabeth Smith for providing the and strains and their critical discussion on the manuscript. We thank the proteomics core facility at UT Southwestern Medical Center for LC‐MS/MS analysis. This work was supported by the National Institutes of Health (NIH) [grant numbers: R01GM083122 to DN, and 5R01GM051173; Emory University Subaward T735204 to M.W] and the Cancer Prevention and Research Institute of Texas (CPRIT) [grant numbers: RR140082 to DN]. The UT Southwestern Cryo‐Electron Microscopy Facility is supported in part by the CPRIT Core Facility Support Award RP170644. This research was supported in part by the computational resources provided by the BioHPC supercomputing facility located in the Lyda Hill Department of Bioinformatics, UT Southwestern Medical Center. pf16D2 pf16D2;PF16 Publisher Copyright: {\textcopyright} 2021 Federation of American Societies for Experimental Biology",
year = "2021",
month = jun,
doi = "10.1096/fj.202001857R",
language = "English (US)",
volume = "35",
journal = "FASEB Journal",
issn = "0892-6638",
publisher = "FASEB",
number = "6",
}