Different effects of Tetrahymena IFT172 domains on anterograde and retrograde intraflagellar transport.
Intraflagellar transport (IFT) particles are multiprotein complexes that move bidirectionally along the cilium/flagellum. The Tetrahymena IFT172 gene encodes a protein with an N-terminal WD domain (WDD) and a C-terminal repeat domain (RPD). Epitope-tagged Ift172p localized to the basal body and in cilia along the axoneme, and IFT172 knockout cells lost cilia and motility. Using serial deletion constructs to rescue the knockout cells, we found that neither the WDD nor the RPD alone is sufficient to assemble cilia. Ift172p containing only the WDD or the RPD failed to enter cilia. Constructs with a partial truncation of the RPD still rescued although cilia were assembled less efficiently, indicating that the WDD and a part of the RPD are sufficient for anterograde transport. Partial truncation of the RPD caused the accumulation of truncated Ift172p itself and of Ift88p at ciliary tips, suggesting that IFT turnaround or retrograde transport was affected. These results implicate different regions of Ift172p in different steps of the IFT process.
Tsao
Che-Chia
CC
Department of Biology, University of Rochester, Rochester, NY 14627, USA.
Gorovsky
Martin A
MA
D000595:Amino Acid Sequence; D000818:Animals; D001693:Biological Transport, Active; D002923:Cilia / Q000378:metabolism; D017124:Conserved Sequence; D005407:Flagella / Q000378:metabolism*; D017353:Gene Deletion; D017125:Genes, Protozoan; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013769:Tetrahymena pyriformis / Q000235:genetics / Q000378:metabolism*
D047908:Intracellular Signaling Peptides and Proteins; D015800:Protozoan Proteins