Molecular determinants of myosin-mediated coupling of actin assembly to endocytic sites. (A) Schematic diagram of Myo5 domains and deletion mutants analyzed. Domain boundaries are marked with the corresponding amino acid number. All mutants were linked to a C-terminal 13Myc tag. (B) Quantification of the proportion of cells harboring the indicated MYO5 truncation mutant displaying cytoplasmic actin comets in epifluorescence videos. Each data point represents a separate experiment during which at least 70 cells were observed. Data points for MYO5 and myo5-TH1Δ are repeated from Fig. 1 C. Asterisks denote statistical significance compared with MYO5 or between bracketed variants after one-way ANOVA (F = 18.88) followed by Sidak’s multiple comparisons test. Error bars are SD. (C–E) Stills from epifluorescence videos of cells endogenously expressing Sla1-GFP (green) and Abp1-mRFP (magenta). Yellow arrowheads indicate cytoplasmic actin comets in mutants. See Videos 12, 13, and 14. (F) Growth of cells harboring truncation mutations in MYO5 on YPD plates. Photos are representative of results from three separate experiments. (G) Schematic diagram illustrating membrane anchoring of actin assembly factors by Myo5. All cells are myo3Δ.