Fig. 2. IC-GFP expression in an IC-null background. (a) IC expression. Western blot of cell lysates probed with IC antibody IC144 (Ma et al., 1999). Lane 1, wild type; lane 2, IC-GFP-expressing cell line; lane 3, cell line (from 2) with disrupted gene for IC. (b) IC-GFP associates with dynein complex. Western blots of cell lysate (lane 3) or immunoprecipitates (lanes 1 and 2) were probed with anti-IC. Dynein was immunoprecipitated using the dynein heavy chain antibody NW127 (lane 1) and dynactin immunoprecipitated using the capping protein ß antibody R18 (lane 2) (Ma et al., 1999). (c) IC-GFP shows a punctate localization along linear tracks in fixed cells. The nucleus appears as a darker round region in the center. (d) Linear tracks of dynein movement visualized by superimposing a time-lapse series of dynein-GFP images collected from a living cell.