IRSp53 , one of the key components of the cytoskeleton is thought to connect to the tumor producing protein Eps8. IRSp53 is synergistically activated by the combined action of Cdc42 and binding of Eps8, which is upregulated in metastatic cancers.
Co-authors Tatyana Svitkina and Changsong Yang from the Penn Department of Biology, brought their expertise with living cells to the study. By introducing normal and mutant proteins into cells they could see how these proteins induced filopodia to form. The team found that mutations in critical regions of IRSp53 can either lead to enhanced or reduced filopodia formation and, as a consequence, cell motility. "This finding shows how all these different proteins converge on IRSp53 to execute precise cellular functions, and that when one factor is disrupted, other proteins are affected down the activity pathway," says Dominguez.
The team's next steps will be to screen libraries of small molecule inhibitors that interfere with the IRSp53-Eps8 interaction, to figure out how to stop unwanted cell movement before it gets too far.