Function and Regulation of the Divisome for Mitochondrial Fission

Abstract

Mitochondria form dynamic networks in cells, balanced by the flux of iterative organelle fusion and fission events. We now appreciate that mitochondrial fission also represents an endpoint event in a signalling axis that allows cells to sense and respond to external cues. The fission process is orchestrated by membrane-associated adaptors, influenced by organellar and cytoskeletal interactions and ultimately executed by the dynamin-like GTPase, Drp1. Here, we invoke the framework of the 'mitochondrial divisome' – conceptually and operationally similar to the bacterial cell division machinery. We review the functional and regulatory aspects of the mitochondrial divisome and against this framework, parse the core from the accessory machinery. In so doing, we transition from a phenomenological to a mechanistic understanding of the fission process.