Interestingly,three of the proteins in ERMES contain lipid-binding SMP domains and thus could facilitate lipid exchange
between the ER and mitochondria.
Consistent with this possibility, cells lacking ERMES have reduced ER–mitochondria contacts and mitochondria from these
cells have altered phospholipid composition including significantly reduced levels of PE and CL.
It may be that the ERMES complex is involved in moving lipids in specific conditions, such as during mitochondrial
division or mitophagy, in which the ERMES complex has been found to be involved .
Alternatively, ERMES may not directly facilitate lipid exchange. In either case, it is clear that other complexes that tether the ER and mitochondria and facilitate lipid exchange remain to be identified.