Mitochondrial fission is a complex process in which a single mitochondrion undergoes division to produce two daughter mitochondria. This mechanism is regulated by dynamin-like protein 1 (Drp1), which is part of the large GTPase enzyme system found in the cytoplasm. The steps of mitochondrial fission are described below.
DRP1 undergoes translocation to the mitochondria with only a small percentage (3–5%) reaching this destination.
Under stress conditions, oligomerized Drp1 is recruited to the outer mitochondrial membrane (OMM) causing the narrowing of the mitochondrial membrane in a GTPase-dependent manner.
The OMM and inner mitochondrial membrane (IMM) begin to separate, creating two distinct mitochondrial compartments.
The separated OMM and IMM are then reconnected, ensuring that they rejoin in the correct orientation.
Throughout the fission process, there are mechanisms to prevent significant loss of soluble proteins from the mitochondrial matrix and intermembrane space.
Mitochondrial proteins and mitochondrial DNA (mtDNA) are actively divided to ensure that each resulting daughter organelle has the necessary components for normal functioning.
The final outcome of mitochondrial fission is the generation of two daughter organelles, each with preserved soluble proteins, correct membrane structure, and the necessary genetic material (mtDNA).