VESICLE, MITOCHONDRIAL, AND PLASTID DIVISION MACHINERIES WITH EMPHASIS ON DYNAMIN AND ELECTRON-DENSE RINGS

The original eukaryotic cells contained at least one set of double-membranebounded organelles (cell nucleus and mitochondria) and single-membranebounded organelles [endoplasmic reticulum, Golgi apparatus, lysosomes (vacuoies), and microbodies (peroxisomes)]. An increase in the number of organelles accompanied the evolution of these cells into Amoebozoa and Opisthokonta. Furthermore, the basic cells, containing mitochondria, engulfed photosynthetic Cyanobacteria, which were converted to plastids, and the cells thereby evolved into cells characteristic of the Bikonta. How did basic single-and double-membrane-bounded organelles originate from bacteria-like cells during early eukaryotic evolution? To answer this question, the important roles of the GTPase dynamin- and electron-dense rings in the promotion of diverse cellular activities in eukaryotes, including endocytosis, vesicular transport, mitochondrial division, and plastid division, must be considered. In this review, vesicle division, mitochondriat division, and plastid division machineries, including the dynamin- and electron-dense rings, and their roles in the origin and biogenesis of organelles in eukaryote cells are summarized.