Fig. 8. Decreased recycling correlates with increased motility in PtK1 cells. (A) Transferrin recycling in cells transiently expressing various Rab mutants measured as fluorescent intensity of Alexa-568-transferrin retained inside the cells at the end of a 30-minute chase period, and expressed as a percentage of total transferrin bound at the beginning of experiment. (B) Recycling efficiency in cells transiently expressing various Rab mutants, expressed as a percentage of neighboring control cell values. (C) Velocities of cells transiently expressing various Rab mutants. (D) Correlation between cell velocity (as a percentage of control) and transferrin recycling (as a percentage of total transferrin bound at the beginning of the experiment). All data points are mean±s.e.m., calculated from at least three experiments, 20-40 cells per experiment.