Super-resolution microscope allows visualization of the mechanism that maintains cell polarity

Cells are not uniform spheres; they generally come in a variety of disparate shapes. In the broadest sense, this variation in shapes is known as cell polarity, and it is an essential property for a variety of cell functions. Growth in accordance with their polarity allows cells to shape themselves in forms appropriate to their function. It has been found that the establishment and maintenance of polarity is governed by the interdependent relationship between the polarity marker protein on the plasma membrane (cell membrane), actin, the microtubule cytoskeleton, and membrane vesicle transport. The polarity marker determines the polarity site, and with membrane vesicle transport toward it, site-specific growth (polarity growth) is achieved. However, when the plasma membrane elongates due to fusion of membrane vesicles, there have been questions about how polarity markers are maintained without being scattered over the elongated plasma membrane.

Y. Ishitsuka, N. Savage, Y. Li, A. Bergs, N. Gru n, D. Kohler, R. Donnelly, G. U. Nienhaus, R. Fischer, N. Takeshita. Superresolution microscopy reveals a dynamic picture of cell polarity maintenance during directional growth. Science Advances, 2015; 1 (10): e1500947 DOI: 10.1126/sciadv.1500947

Transient polarity model. Credit: Image courtesy of University of Tsukuba