May 2, 2011

The cytoskeleton is made of actin, microtubules, and intermediate filaments. Sometimes, those poor intermediate filaments fall out of the spotlight by the stage hogs, actin and microtubules. This is unfortunate, because intermediate filaments are quite beautiful, as you’ll see in today’s images.

Vimentin is an intermediate filament protein found in migrating cells. Migrating cells have lamellipodia, which are dynamic membrane ruffles found at the front of a migrating cell, and a recent paper looks at the role of vimentin in migration. Helfand and colleagues found that the disassembly of vimentin intermediate filaments at the cell’s periphery is important for the formation of lamellipodia and for motility. As seen in the images above, motile cells (top) do not have vimentin intermediate filaments in lamellipodia, and instead have a decreasing presence of long filaments as they approach the lamellipodia (a,b) and non-filamentous vimentin at the cell’s edge (c). Cells lacking lamellipodia (bottom), however, have vimentin intermediate filaments that extend to the cell’s periphery.

Helfand, B., Mendez, M., Murthy, S., Shumaker, D., Grin, B., Mahammad, S., Aebi, U., Wedig, T., Wu, Y., Hahn, K., Inagaki, M., Herrmann, H., & Goldman, R. (2011). Vimentin Organization Modulates the Formation of Lamellipodia Molecular Biology of the Cell DOI: 10.1091/mbc.E10-08-0699