title: IFT57 stabilizes the assembled intraflagellar transport complex and mediates transport of motility-related flagellar cargo.
abstract: Intraflagellar transport (IFT) is essential for the assembly and maintenance of flagella and cilia. Recent biochemical studies have shown that IFT complex B (IFT-B) is comprised of two subcomplexes, IFT-B1 and IFT-B2. The IFT-B2 subunit IFT57 lies at the interface between IFT-B1 and IFT-B2. Here, using aChlamydomonasreinhardtiimutant for IFT57, we tested whether IFT57 is required for IFT-B complex assembly by bridging IFT-B1 and IFT-B2 together. In theift57-1mutant, levels of IFT57 and other IFT-B proteins were greatly reduced at the whole-cell level. However, strikingly, in the protease-free flagellar compartment, while the level of IFT57 was reduced, the levels of other IFT particle proteins were not concomitantly reduced but were present at the wild-type level. The IFT movement of the IFT57-deficient IFT particles was also unchanged. Moreover, IFT57 depletion disrupted the flagellar waveform, leading to cell swimming defects. Analysis of the mutant flagellar protein composition showed that certain axonemal proteins were altered. Taken together, these findings suggest that IFT57 does not play an essential structural role in the IFT particle complex but rather functions to prevent it from degradation. Additionally, IFT57 is involved in transporting specific motility-related proteins.
authors.affiliation: Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA.
authors.forename: Xue
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hernandez
authors.affiliation: Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA.
authors.forename: Catherine
authors.initials: C
authors.lastname: Hernandez
authors.affiliation: Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA.
authors.forename: Zhaolan
authors.initials: Z
authors.lastname: Ding
authors.affiliation: Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA.
authors.forename: Beiyan
authors.initials: B
authors.lastname: Nan
authors.affiliation: Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA.
authors.forename: Karl
authors.initials: K
authors.lastname: Aufderheide
authors.affiliation: Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA hqin@bio.tamu.edu.
authors.forename: Hongmin
authors.identifier: 0000-0002-0045-5780
authors.initials: H
authors.lastname: Qin
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics; D048868:Adaptor Proteins, Signal Transducing; D052818:Autotrophic Processes; D054468:Axoneme / Q000378:metabolism; D001692:Biological Transport; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D004398:Dyneins / Q000378:metabolism; D005407:Flagella / Q000378:metabolism*; D009068:Movement; D016254:Mutagenesis, Insertional / Q000235:genetics; D009154:Mutation / Q000235:genetics; D010940:Plant Proteins / Q000378:metabolism*; D055550:Protein Stability; D021381:Protein Transport
chemical_list: D020121:5' Untranslated Regions; D048868:Adaptor Proteins, Signal Transducing; D010940:Plant Proteins; D004398:Dyneins
keywords: Cilia; Flagella; Flagellar assembly; Flagellar motility; IFT complex; IFT particles; IFT57