Cells lacking Raf-1 (bottom) migrate poorly.
R af-1 signaling is known to be important for proliferation, differentiation, and survival. Now, Ehrenreiter et al. report that it is required for cell migration and wound healing (
page 955). Unlike other Raf-1 functions, this one doesn't require Raf-1 kinase activity, a theme the researchers think will be recurrent in future Raf-1 biology.When Raf-1 is knocked out in the epidermis of animals carrying conditional Raf-1 alleles, the epidermal structure remains normal. However, wounds heal slowly in the absence of Raf-1, despite normal cell proliferation in the epidermis. In culture, Raf-1–deficient cells do not migrate normally and appear rounded and contracted with dense cortical actin structures.
This suggests that either Rho or its downstream effector, Rok-α kinase, is hyperactive. Biochemical experiments showed that Raf-1 was required for Rok-α inhibition in keratinocytes and fibroblasts, and that inhibition of Rok-α...
