Mitofusin 2 Builds a Bridge between ER and Mitochondria

Mutations in mitofusin 2 (MFN2), a dynamin-like GTPase required for mitochondrial fusion, cause the peripheral neuropathy Charcot-Marie-Tooth type 2A. In a recent report in Nature, demonstrate a new function of MFN2—tethering the endoplasmic reticulum and mitochondria to control the efficiency of mitochondrial uptake of Ca2+ ions.