FIGURE 1:

The Kif18A C-terminus targets plus end–directed motors to K-fibers but is not sufficient for accumulation at K-fiber ends. (A) Schematic of Kif18A-tail chimeras. Numbers in parentheses indicate the amino acids used in each fragment. (B) Western blots of lysates transfected with the indicated siRNAs and GFP-tagged transgenes. Purified Kif18A-GFP (30 ng) was included for comparison. Blots were probed with anti-Kif18A (top) and anti-GAPDH (bottom) antibodies. The amount of Kif18A expressed in Kif18A siRNA–treated cells from three independent experiments is 9.8 ± 1.3% relative to controls. Note that Kif18A-770 does not contain the epitope recognized by the anti-Kif18A antibody. An anti-GFP blot of this sample is included in Supplemental Figure S2. (C) Fluorescence micrographs of the indicated GFP-tagged kinesins (green) in Kif18A-depleted HeLa cells immunostained with ACA (centromeres, red) and tubulin (blue). (D) Line scans of GFP-tagged kinesin (green trace) relative to tubulin (blue trace) and ACA fluorescence (red trace) along peripheral K-fibers.