Figure 6

Role of Drp1 on vMIA trafficking and clustering on the mitochondria. (a) HFFs were lipofected with vectors expressing vMIA-CFP (pseudocolored green) and mCherry-Drp1 (red)⁵⁷. Cells were imaged by confocal microscopy and single slice of the deconvolved images is shown as monochrome and pseudocolored images as above. (b) Confocal image of a Drp1-null MEF transiently expressing vMIA-CFP (pseudocolored green) and Tom20-YFP (pseudocolored red). Monochrome images show the individual channels and the merged image demonstrates vMIA colocalization with Tom20-YFP. A zoom of the boxed region of interest is shown. (c) The fluorescence lifetime comparison of cytosolic EGFP (τ = 3.40 ± 0.013 ns, n = 120 regions from 12 cells) and vMIA-EGFP (τ = 3.04 ± 0.026 ns, n = 130 regions from 13 cells) in Drp1-null MEFs. (d) A single plane from an MSIM z-stack images showing clustered distribution of vMIA-EGFP on the OMM of a transfected Drp1-null MEF. A zoom of a single mitochondrion shows vMIA clustering. (e) Normalized pixel intensities of a line shown along the mitochondrion in inset of panel d. (f) Box plot showing the distribution of vMIA clusters (n = 40 cells) in WT MEFs and Drp1-null MEFs. ****Indicates p < 0.0001.