Mitochondria's dividER.

A recent paper by Friedman et a., Science 2011 reinforces the tight connection between the ER and the mitochondria. It was previously known that ER and mitochondria exhibit important and dynamic contacts. Now Friedman et al. report that the ER is involved in the division process of the mitochondria, reinforcing the tight link between the ER and mitochondaria. This result demonstrates the decisive role of the eukaryotic endomembrane system in the regulation of the organelle's faith.

But what's that to do with the PVC bacteria? Well, the PVC endomembrane has been suggested to be linked to the birth of the eukaryotic one. Even more,Devos & Reynaud PRSB (2011) have suggested that the eukaryotic endomembrane system originated by the internalization of the bacterial periplasm. The concomitant internalization of the ancestor of the symbiont with the periplasm establishes the endomembrane system at the same time as the mitochondria. This hypothesis suggests a tight interaction between the endomembrane system and the mitochondria. And this is exactly what the Friedman paper demonstrates.

The connection between the ER and the mitochodria is tightened by a study showing that the ER tether mitochondria specifically at the tip of the growing bud in Saccharomyces cerevisiae.