HA-tagged CMF22 rescues the motility defect of CMF22-knockdown cells. (A) Western blot of total protein prepared from CMF22-UKD cells or CMF22-UKD-Ri cells probed with anti-HA or antitubulin antibody, as indicated. UKD-Ri cells contain an RNAi-immune HA-tagged CMF22 gene; see the text for details. (B) Northern blot of total RNA prepared from CMF22-UKD or CMF22-UKD-Ri cells grown in the absence or presence of Tet, as indicated. Open arrowhead, endogenous CMF22 mRNA; filled arrowhead, HA-tagged mRNA. Membranes were probed with a DNA fragment specific to the CMF22 ORF (top), and rRNA is shown as a loading control (bottom). (C) Growth curve of CMF22-UKD-Ri cells grown in the absence or presence of Tet, as indicated. (D and E) Motility traces of CMF22-UKD-Ri cells grown in the absence or presence of Tet, as indicated.