A closer look at what happens when organelles get up close and personal
Mammalian cells are loaded with membrane-bound organelles that compartmentalise their work according to various cellular functions. Just like in a real factory, different 'departments' sometimes work together. Execution of biological processes such as phospholipid biosynthesis and calcium signalling require two organelles to be close but not touching. Perhaps the best known interorganelle contact points are the mitochondria–endoplasmic reticulum contact sites (MERCs). These dynamic structures change in response to the metabolic state of the cell, with the contact surface area and gap width being important structural elements. The multifunctional roles of MERCs are largely unknown, but recent evidence suggests their implication in disease as well as health with a link to lipid metabolism in Alzheimer's disease. The EU-funded MERCURY project is investigating the regulation of MERC dynamics by small molecules through the screening of bioactive molecules and the identification of their protein targets.