Organization of organelles and VAMP-associated vesicular transport systems in differentiating skeletal muscle cells.

Vesicular transport plays an important role in the regulation of cellular function and differentiation of the cell, and intracellular vesicles play a role in the delivery of membrane components and in sorting membrane proteins to appropriate domains in organelles and the plasma membrane. Research on vesicular transport in differentiating cells has mostly focused on neurons and epithelial cells, and few such studies have been carried out on skeletal muscle cells. Skeletal muscle cells have specialized organelles and plasma membrane domains, including T-tubules, sarcoplasmic reticulum, neuromuscular junctions, and myotendinous junctions. The differentiation of skeletal muscle cells is achieved by multiple steps, i.e., proliferation of myoblasts, formation of myotubes by cell-cell fusion, and maturation of myotubes into myofibers. Systematic vesicular transport is expected to play a role in the maintenance and development of skeletal muscle cells. Here, we review a map of the vesicular transport system during the differentiation of skeletal muscle cells. The characteristics of organelle arrangement in myotubes are described according to morphological studies. Vesicular transport in myotubes is explained by the expression profiles of soluble N-ethylmaleimide-sensitive factor attachment protein receptor proteins.