Figure 1.

Mitochondrial dynamics in eukaryotic cells. Diverse processes contribute to generation and degradation of mitochondria within cells. During fission, recognition of activated dynamin-related protein 1 (DRP1) by surface receptors (fission protein 1, mitochondrial fission factor, mitochondrial dynamic protein 49, and mitochondrial dynamic protein 51) leads to fragmentation of the outer mitochondrial membrane (OMM) and formation of a new mitochondrion. Mitochondria may acquire an elongated design by fusion, where mitochondrial membranes tether through fusion proteins in the inner mitochondrial membrane (IMM), such as optic atrophy 1 (OPA1), and OMM, such as mitofusin 1 (MFN1) and MFN2.