Cell Fusion: Merging Membranes and Making Muscle

Cell–cell fusion in different systems is accomplished by specific fusogenic proteins that are notable for their structural and functional diversity. Vertebrate myoblast fusion is driven by two independent skeletal muscle-specific proteins, myomaker and myomerger, whose expression are tightly regulated to the time of membrane fusion. Myomaker and myomerger function at distinct membrane remodeling steps, creating a divided fusion reaction in myoblasts. Cell fusion is essential for the development of multicellular organisms, and plays a key role in the formation of various cell types and tissues. Recent findings have highlighted the varied protein machinery that drives plasma-membrane merger in different systems, which is characterized by diverse structural and functional elements. We highlight the discovery and activities of several key sets of fusion proteins that together offer an evolving perspective on cell membrane fusion. We also emphasize recent discoveries in vertebrate myoblast fusion in skeletal muscle, which is composed of numerous multinucleated myofibers formed by the fusion of progenitor cells during development. Cell fusion is essential for the development of multicellular organisms, and plays a key role in the formation of various cell types and tissues. Recent findings have highlighted the varied protein machinery that drives plasma-membrane merger in different systems, which is characterized by diverse structural and functional elements. We highlight the discovery and activities of several key sets of fusion proteins that together offer an evolving perspective on cell membrane fusion. We also emphasize recent discoveries in vertebrate myoblast fusion in skeletal muscle, which is composed of numerous multinucleated myofibers formed by the fusion of progenitor cells during development.