A good chunk of my personal pride is about my ability to wear several hats. I can cook a mean dinner, read that awesome new Myo10 paper, and fix a leaking faucet all while braiding my little girl’s hair and constructing a garden scene out of PlayDoh. So, today’s image makes me tip my many hats to Myo10 and its newly-recognized role in polarized cells.
Myo10 is a member of the giant family of myosin actin motors. Myo10 localizes to the tips of thin actin-rich membrane extensions, called filopodia, in non-polarized fibroblast-like cells and plays an important role in the formation and function of filopodia. A recent paper describes the role of Myo10 in a very different type of cell—the polarized epithelial cell. According to Liu and colleagues, Myo10 is important during formation of the cell-cell junctions that adhere epithelial cells together in a highly organized sheet. Myo10 is found at cell-cell contact points during junction formation, and helps ensure the timely localization of essential junction proteins. In addition, the leak-proof barrier function of an epithelial sheet is compromised in cells with reduced levels of Myo10. The images above show epithelial cysts, frequently used to model the three-dimensional formation of epithelial tissue in culture. Cysts with normal levels of Myo10 (top row) developed a single lumen, while cysts with reduced levels of Myo10 frequently had more than one lumen (bottom row), pointing to a role for Myo10 in epithelial morphogenesis. Junctional markers (ZO-1 is green, E-cadherin is red), however, are still properly localized in cysts with reduced Myo10.
Liu, K., Jacobs, D., Dunn, B., Fanning, A., & Cheney, R. (2012). Myosin-X Functions in Polarized Epithelial Cells Molecular Biology of the Cell DOI: 10.1091/mbc.E11-04-0358