Cells in D.C.: The American Society for Cell Biology : Washington, D.C. December 4–8, 2004

Flagella and cilia are constantly turning over proteins at their tips. Assembly at the tip and removal of turnover products require the intraflagellar transport (IFT) system, which uses axonemal microtubules as tracks to drop off flagellar tip proteins and return turnover products to the cell body. The change in IFT direction at the tip was discussed by Lotte Pedersen (Yale University, New Haven, CT), whose work implicates IFT172 as an orchestrator of IFT traffic at flagellar tips.Along with different cargo, the two IFT directions come with different motors—kinesin-2 brings the IFT complex and its cargo out to the tip, and cytoplasmic dynein 1b/2 drives retrograde transport back to the cell body. Axonemal microtubules point their plus ends toward flagellar tips, so Pedersen thought perhaps plus-end tracking proteins might be involved in IFT turnaround at the...