RAC1 and viral infectious disease: Therefore, to test whether AMPK controlled actin-dependent remodeling independent of viral infection, we treated cells with phorbol myristic acid (PMA), which induces cells to undergo high levels of actin-mediated ruffling and lamellipodia formation; this is dependent on Rac1, a small Rho family GTPase that is also required for macropinocytosis and vaccinia infection [7], [35], [36], [37].