Myo1 displays cell cycle–regulated dynamics at the division site. (A–C) Myo1 is mobile at the division site in small-budded cells (A), becomes less mobile in large-budded cells (B), and is immobilized during cytokinesis (C), indicated by the presence of a double septin ring at the division site, which is not shown in any figure but can be seen in the figure-associated video. A half of the Myo1-GFP ring from cells at different stages of the cell cycle (indicated by bud size) of the strain XDY286 (MYO1-GFP CDC3-RFP) was photobleached, and fluorescence recovery in the bleached and unbleached regions was followed over time. Except where noted, FRAP analysis was performed in a similar way throughout the study. Quantitative analysis and the corresponding kymograph for a single representative cell are shown in each plot of the main figures. Individual recovery curves for all cells examined for a given protein at a specific cell cycle stage and their associated quantitative analyses are shown in Figs. S3 and S4. (D–F) Myo1 becomes immobilized in late anaphase or telophase. Large-budded cells (n = 12) of the strain YEF6036 (MYO1-GFP CDC3-RFP NUP57-RFP) at different phases of the cell cycle (indicated by the nuclear pore protein Nup57-RFP) were subjected to FRAP analysis to determine the precise timing of Myo1 immobilization during the cell cycle. WT, wild type.