Figure 2.

Movement of HM19^FullLZ-associated mitochondria vesicles on demembraned cells. The movement of Halo-HM19^FullLZ-associated HMF was observed with a TIRF microscope at 5 fps in the presence of 1 mM ATP, and the run length and velocity were analyzed. A, representative movement of HMF prepared from HM19^FullLZ-expressing cells on demembraned U2OS cells. Halo-HM19^FullLZ was expressed in HEK293T cells and stained with R110 direct reagent. The HMF prepared as described in the “Experimental procedures” section was added to demembraned U2OS cells, and the movement was observed with a TIRF microscope in the presence of 1 mM ATP (Movie S1). The bar represents 1 μm. B, run length of HM19^FullLZ-associated mitochondria vesicles. The position of the moving light spot was tracked, and the run length was calculated. The solid line shows the best fit to a single exponential equation, R₀e^−r/λ, where R₀ is the initial frequency extrapolated to zero run length, r is the run length, and λ is the average run length. The average run length was 0.37 ± 0.09 μm (SEM, n = 48). C, the velocity of HM19^FullLZ-associated mitochondria vesicles. The distribution was fitted to two Gaussian equations with the mean velocity of 27.8 ± 1.0 and 61.9 ± 6.4 nm/s (SEM, n = 48), respectively. HEK293T, human embryonic kidney 293T cell line; HM19, human Myo19; HMF, heavy mitochondrial fraction; LZ, leucine zipper; R110, rhodamine 110; TIRF, total internal reflection fluorescence.