Open AccessInteraction of WDR60 intermediate chain with TCTEX1D2 light chain of the dynein-2 complex is crucial for ciliary protein trafficking
Author(s) -
Yuki Hamada,
Yuta Tsurumi,
Shohei Nozaki,
Yohei Katoh,
Kazuhisa Nakayama
Publication year - 2018
Publication title -
molecular biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.463
H-Index - 225
eISSN - 1939-4586
pISSN - 1059-1524
DOI - 10.1091/mbc.e18-03-0173
Subject(s) - dynein , intraflagellar transport , cilium , biology , microbiology and biotechnology , dynein atpase , dynactin , immunoprecipitation , microtubule , ciliopathy , protein subunit , flagellum , genetics , gene , phenotype
The dynein-2 complex mediates trafficking of ciliary proteins by powering the intraflagellar transport (IFT) machinery containing IFT-A and IFT-B complexes. Although 11 subunits are known to constitute the dynein-2 complex, with several light-chain subunits shared by the dynein-1 complex, the overall architecture of the dynein-2 complex has not been fully clarified. Utilizing the visible immunoprecipitation assay, we demonstrated the interaction modes among the dynein-2 subunits, including previously undefined interactions, such as that between WDR60 and the TCTEX1D2–DYNLT1/DYNLT3 dimer. The dynein-2 complex can be divided into three subcomplexes, namely DYNC2H1–DYNC2LI1, WDR34–DYNLL1/DYNLL2–DYNLRB1/DYNLRB2, and WDR60–TCTEX1D2–DYNLT1/DYNLT3. We established cell lines lacking WDR60 or TCTEX1D2, both of which are dynein-2–specific subunits encoded by ciliopathy-causing genes, and found that both WDR60-knockout (KO) and TCTEX1D2-KO cells show defects in retrograde ciliary protein trafficking, with WDR60-KO cells demonstrating more severe defects probably due to failed assembly of the dynein-2 complex. The exogenous expression of a WDR60 mutant lacking TCTEX1D2 binding partially restored retrograde trafficking to a level comparable to that of TCTEX1D2-KO cells. Thus, our results demonstrated that WDR60 plays a major role and TCTEX1D2 plays an auxiliary role in the dynein-2 complex to mediate retrograde ciliary protein trafficking.