Figure 3.

Upregulation of biophysical parameters of mitochondrial kinetics by KBD of RanBP2. Dot-box plot analyses are shown in (a–d). The tables accompanying dot-box plots represent the corresponding median values for the represented datasets. (a) KBD compared with KBD* and mock-transfected cells temporally increases mitochondrial motility and (b) decreases duration of pauses between anterograde motility events. (c) The duration of pauses between anterograde (A) and retrograde (R) motile events in the same direction (A–A, R–R) are smaller than those upon directional switches (R–A, A–R), and these differences are not affected by KBD or KBD^* (data not shown). (d) KBD compared with KBD* and mock-transfected cells temporally increases the frequency of directional changes of mitochondria. (e) Three-dimensional histogram showing that an increase in the persistency of mitochondrial anterograde motility is contingent upon KBD, but not KBD^* or mock-transfected cells (chi-squared contingency test, p < 0.001, χ² = 39.475, Cramer's contingency coefficient ϕ = 0.631), and upon time of post-transfection (chi-squared contingency test, p < 0.001, χ² = 38.22, Cramer's contingency coefficient ϕ = 0.58). Asterisks in medians denote significant differences (Mood's median test, α = 0.01); symbols ‘o’, ‘oo’ and hash are mitochondrial pools significantly different from non-transfected (o), KBD^* (oo) and other times of transfection with the same construct (hash); n, number of mitochondria; Mock, mock-transfected; KBD and KBD^* are wild-type and mutant kinesin-binding domain of RanBP2, respectively; transf., post-transfection time; n.s., not significant. (a–d) Mann–Whitney test, p < 0.001.