Watching your child learn to crawl, you realize how much coordination she needs to get up on all fours and move forward, working both sides of her body. You are convinced that your child is totally gifted and brilliant. Well, I have news for you…cells have a lot more to sort out in order to crawl. As you sheepishly compare your child’s brilliance to a cell and admit defeat (except for me, of course…my daughter really IS brilliant), take a moment to look at today’s beautiful images from a paper on cell migration.
When a cell is crawling, it first reaches out using membrane protrusions. At the leading edge of these protrusions, the cell will adhere to the underlying matrix. These nascent adhesions serve as anchors to the surface and give the crawling cell traction. Cell-matrix adhesions go through dynamic cycles of formation as nascent adhesions, maturation into focal adhesions, and turnover using a well-studied set of cytoskeletal proteins and regulators, but how these adhesions form and mature is not completely understood. Lawson and colleagues recently published results showing that a protein called FAK (focal adhesion kinase) promotes the recruitment of an adhesion protein called talin to nascent adhesions. Talin binds to integrin, a key adhesion protein, and was previously thought to recruit FAK to nascent adhesions. In the images above, a control cell (left) shows localization of talin (green) to nascent adhesions (red). However, without FAK (right), talin is not recruited to nascent adhesions.
Lawson, C., Lim, S., Uryu, S., Chen, X., Calderwood, D., & Schlaepfer, D. (2012). FAK promotes recruitment of talin to nascent adhesions to control cell motility originally published in the Journal of Cell Biology, 196 (2), 223-232 DOI: 10.1083/jcb.201108078