News
Keeping cells in shape
Published on October 28, 2011
Scientists from IRIC make the cover of the prestigious scientific journal The Journal of Cell Biology with a recent discovery on cell division
The team of Dr. Sébastien Carreno, principal investigator at IRIC, and colleagues from the University Paul Sabatier of Toulouse in France, have identified two molecular mechanisms responsible for changes in the shape of a dividing cell. A better understanding of this extremely complex process could open new avenues for the development of anti-cancer therapies. Their recent publication made the cover of the October 3rd issue of the prestigious scientific journal The Journal of Cell Biology.
Cell division is a tightly controlled process and its deregulation is often associated with the appearance and growth of a tumour. During mitosis, the shape of a cell changes dramatically on at least two occasions. At the beginning of division, the cell cortex tightens, forcing the cell to round up. Toward the end of mitosis, the poles relax and the cell equator contracts, allowing the cell to stretch and eventually split into two.
The present study focused on a protein called Moesin which belongs to a family of proteins that bind the cell membrane to the cytoskeleton of the cortex, a scaffold of filaments just under the surface, therefore acting as the clips that attach the fabric to the frame of a tent to stabilize the structure. The researchers demonstrated that the position of Moesin reflects the shape of the cell. Thus, during mitosis, Moesin is initially dispersed around the edges of the cell and later concentrates at the equator. Furthermore, changes in the activity of this protein orchestrate changes in tension in the cell cortex, which are largely responsible for changes in cell shape.
Systematically testing all potential regulators of Moesin, the researchers identified two ways to control its activity. The integration of signals from these two cellular pathways determines the position and activity of Moesin and thus the shape of the cell.
The significance of these findings for cancer is evident when one considers that the overabundance of a protein of the same class as Moesin has already been associated with the formation of metastases and thus the development of generalized cancers.
Seeking to push even further our knowledge of mitosis, Dr. Carreno and his team now focus on understanding how the activities of Moesin regulators are themselves modulated during cell division.
A short video clip describing this work is available on the web site of The Journal of Cell Biology at http://jcb-journalclub.rupress.org/2011/10/oct_3_2011.html
Paper cited
Roubinet C, Decelle B, Chicanne G, Dorn JF, Payrastre B, Payre F, Carreno S. (2011) Molecular networks linked by Moesin drive remodeling of the cell cortex during mitosis. J Cell Biol. 195:99-112.