Tetrahymena IFT122A is not essential for cilia assembly but plays a role in returning IFT proteins from the ciliary tip to the cell body.
Intraflagellar transport (IFT) moves multiple protein particles composed of two biochemically distinct complexes, IFT-A and IFT-B, bi-directionally within cilia and is essential for cilia assembly and maintenance. We identified an ORF from the Tetrahymena macronuclear genome sequence, encoding IFT122A, an ortholog of an IFT-A complex protein. Tetrahymena IFT122A is induced during cilia regeneration, and epitope-tagged Ift122Ap could be detected in isolated cilia. IFT122A knockout cells still assembled cilia, albeit with lower efficiency, and could regenerate amputated cilia. Ift172p and Ift88p, two IFT-B complex proteins that localized mainly to basal bodies and along the cilia in wild-type cells, became preferentially enriched at the ciliary tips in IFT122A knockout cells. Our results indicate that Tetrahymena IFT122A is not required for anterograde transport-dependent ciliary assembly but plays a role in returning IFT proteins from the ciliary tip to the cell body.
Tsao
Che-Chia
CC
Department of Biology, University of Rochester, Rochester, NY 14627, USA.
Gorovsky
Martin A
MA
D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002923:Cilia / Q000378:metabolism*; D005838:Genotype; D008954:Models, Biological; D009154:Mutation; D016366:Open Reading Frames / Q000235:genetics; D016133:Polymerase Chain Reaction; D021381:Protein Transport; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D013768:Tetrahymena / Q000235:genetics / Q000378:metabolism*
D015800:Protozoan Proteins