FIGURE 13.

Redundancy of membrane contact sites. (A) Overall schematic recapitulating the interconnectivity of organelles in the case of the ER (perinuclear ER included), mitochondria and vacuole implicating ERMES, vCLAMP and NVJ contacts sites. LD are connected to mitochondria and vacuole (shown here via lipophagy) while the vesicular network also connects to the vacuole through a Vps39-HOPS complex redundant to the Vps13-vCLAMP and ERMES. (B) Two distinct vCLAMPs use different subsets of proteins, Vps13 or Vps39, and respectively include proteins Mcp1 or porin Tom40 that could affect lipid desorption through membrane distortion although lipid exchange has not been associated with Vps39-vCLAMP. The ERMES, Vps13-vCLAMP and Vps39-HOPS pathways are redundant. Vps13 is also found at the NVJ under certain conditions. Complexes boxed in light blue constitute redundant pathways. Red arrows indicate lipid exchange activity.