Figure 8.

Model for endosome–mitochondria interactions in nonerythroid cells. (A and B) Comparing the behavior of unmutated hTf- (A) and lock-hTf–endosomal interaction (B) with mitochondria suggests that blocking iron release from Tf–TfR complexes affects the ability of endosomes to interact with mitochondria because of an iron-mediated cargo and/or endosomal milieu alterations. (a) Arrows represent endosomal speed during run; black arrows in lock-hTf indicate higher speeds than dark gray arrows in the case of hTf-endosomes. (b) Arrows represent endosomal speed during kiss; light gray arrow in hTf-endosome indicates slower speed than the dark gray arrow in the case of lock-hTf–endosomes. (c) Length of blue bars with double arrowheads indicates duration of kiss events, which is longer in the case of lock-hTf–endosomes. (d and e) Schematic representations of putative docking complexes involved in iron transfer to mitochondria.