Fig. 5. Disruption of Mlph interaction with Rab27a and MyoVa, but not EB1, affects rescue of melan-ln melanosome transport defects. Melan-ln cells were transfected with plasmids encoding the indicated Mlph point mutant molecules and control proteins. Cells were fixed 48 hours later and stained with antibodies to detect Myc-tagged Mlph and Slp1 protein. Panels A, E, I, M and Q show the distribution of overexpressed protein, panels B, F, J, N and R are transmission images showing the distribution of pigment; panels C, G, K, O and S are inverted and filtered copies of the transmission images showing the distribution of melanosomes and panels D, H, L, P and T are merged images in which the distribution of myc tagged Mlph and Slp1 protein (green) and melanosomes (red) are superimposed. Bars, 20 µm. Arrows in panels A-H and M-T indicate colocalisation of Mlph protein with the cytoplasmic surface of melanosomes. Arrows in panel I indicate association of Mlph with linear actin filaments. Panel U shows quantification of the extent of rescue of melanosome transport by the Mlph point mutants. Rescue efficiency for populations of transfected cells was determined as described in Hume et al. (Hume et al., 2006). Shaded boxes indicate 25th/75th percentile; bars within boxes indicate median values for each population of cells; outer bars indicate 5th/95th percentile; and outer points indicate outliers. The statistical significance of rescue measurements for populations of Mlph mutant transfected cells relative to positive (wild-type Mlph) and negative (Slp1) controls is shown in Table 1.