Regulator of mitochondrial fusion (PubMed:26711011). Acts by forming homo- and heterodimers at the mitochondrial outer membrane and facilitating the formation of PLD6/MitoPLD dimers. May act by regulating phospholipid metabolism via PLD6/MitoPLD (By similarity). Homodimer and heterodimer; forms heterodimers with MIGA1. Interacts with PLD6/MitoPLD. Mitochondrial fragmentation: mitochondria become round and show loss of cristae (PubMed:26711011). Female mice show decreased quality of oocytes (PubMed:26716412). Mice lacking both Miga1 and Miga2 show strongly reduced quality of oocytes and are subfertile (PubMed:26716412). Belongs to the mitoguardin family.