Staining of CORO2B (green) with tubules (red) and DNA (blue) in U-251 MG cells.

Welcome to another HPA image of the week! This week's image was brought to us by citizen scientists in Project Discovery, and specifically by Shiverwarp who found this image while playing Project Discovery in EVE online.

The protein stained in Fig 1. is an image of Coronin, actin binding protein, 2B (CORO2B) found in the focal adhesions and at the plasma membrane of the cell. This sample shows U-251 MG human glioblastoma astrocytoma (brain) cells.

Focal adhesions are transmembrane groups of protein that allow the cell to "grab" the surrounding environment. In the case of cell culture, this means the cell flattens out and adheres to the surface of the plate on which it was grown, however in the body this happens in three dimensions of course. These adhesions not only hold the cell in place and help it keep its shape, but also are essential for cellular motility (Hynes R. O. & Lander A. D. 1992 , Gumbiner B. M. 1996).

As discussed a couple weeks ago, in our post on actin filaments, focal adhesions bind to these filaments and allow the cell pull itself along through the substrate. As the name suggests, CORO2B is an actin binding protein found most prominently at the leading edge of the cell (the edge towards which the cell is moving) near the plasma membrane. This protein binds to actin at this leading edge and helps helps the actin network interact with the outside environment through the focal adhesions.

Focal adhesion are often found to have a high turnover rate in aggressive cancers where cells are highly motile (Nagano M. et al. 2012). As such, proteins involved in focal adhesion and cell migration are often targets of treating invasiveness of such cancers (Bijian K. et al. 2013).

Thanks to the citizen scientists participating in Project Discovery and particularly to Shiverwarp for their contribution to science!