Myoferlin, a Membrane Protein with Emerging Oncogenic Roles

Figure 2

The role of MYOF in membrane trafficking. These trafficking processes have been identified in muscle fibers and other cells. They are also present in cancer cells. MYOF is present at the plasma and nucleus membrane as well as intracellular vesicle. It is involved in exocytosis, endocytosis, receptor internalization and recycling. For example, MYOF mediates endocytosis of transferrin by interacting with caveolin-1 (Cav-1) and dynamin-2 (Dyn-2). MYOF also directs vesicles containing VEGFR-2 to the plasma membrane to promote its surface expression and prevents it from proteasomal degradation. In addition, MYOF is responsible for internalization and recycling of receptors like IGF receptor. MYOF depletion redirects IGF receptor from recycling to a degradation pathway, which leads to mistrafficking of such receptor and disrupts IGF signaling. The secretion of lysosomal enzymes also requires MYOF, suggesting that this protein is widely involved in membrane trafficking.