Limits...
Endosome – mitochondria interactions are modulated by iron release from transferrin

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Using superresolution and quantitative fluorescence microscopy, Das et al. have revealed that iron-transferrin–containing endosomes directly interact with mitochondria, facilitating iron transfer in epithelial cells. Their findings further enrich the repertoire of organelle–organelle direct interactions to accomplish a functional significance.

No MeSH data available.


Related in: MedlinePlus

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.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC5037410&req=5

fig8: 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.

Mentions: Second, we inquired whether alterations in the endosomal cargo, particularly in the iron release ability of Tf–TfR complexes by using lock-hTf, affected endosome–mitochondria interactions. Our quantitative analysis of the duration of kiss events revealed an increased number of longer interactions by the mutant hTf-endosomes with mitochondria. The overall interaction can be perceived to comprise of at least three discrete events: proximity-dependent interaction, functional accomplishment of iron transfer, and the Tf-endosome’s departure from mitochondria. Our results suggest that these docking and release mechanisms may be disrupted when iron release is blocked (Fig. 8). Putative candidates for this docking step are the divalent metal transporter 1 (DMT-1) that was found both in the endosomal membrane as well as in the OMM and the voltage-dependent anion-selective channel (VDAC1) that was shown to colocalize with DMT-1 (Wolff et al., 2014).


Endosome – mitochondria interactions are modulated by iron release from transferrin
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.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5037410&req=5

fig8: 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.
Mentions: Second, we inquired whether alterations in the endosomal cargo, particularly in the iron release ability of Tf–TfR complexes by using lock-hTf, affected endosome–mitochondria interactions. Our quantitative analysis of the duration of kiss events revealed an increased number of longer interactions by the mutant hTf-endosomes with mitochondria. The overall interaction can be perceived to comprise of at least three discrete events: proximity-dependent interaction, functional accomplishment of iron transfer, and the Tf-endosome’s departure from mitochondria. Our results suggest that these docking and release mechanisms may be disrupted when iron release is blocked (Fig. 8). Putative candidates for this docking step are the divalent metal transporter 1 (DMT-1) that was found both in the endosomal membrane as well as in the OMM and the voltage-dependent anion-selective channel (VDAC1) that was shown to colocalize with DMT-1 (Wolff et al., 2014).

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Using superresolution and quantitative fluorescence microscopy, Das et al. have revealed that iron-transferrin–containing endosomes directly interact with mitochondria, facilitating iron transfer in epithelial cells. Their findings further enrich the repertoire of organelle–organelle direct interactions to accomplish a functional significance.

No MeSH data available.


Related in: MedlinePlus