Figure 1.

Effects of GEF-H1 activation. The activity of Rho GTPases is determined by bound guanine nucleotides. When GEF-H1 facilitates the exchange of GDP for GTP on RhoA, RhoA is activated and signals this changed activation state via its downstream effectors. Of the RhoA effectors, Rho-associated coiled-coil containing protein kinases 1 and 2 (ROCK1 and ROCK2) are amongst the most important as they regulate the organization of the actin cytoskeleton and influence cellular processes (e.g. cell migration) that are mediated by actin cytoskeleton dynamics. Abbreviations: MYPT1, myosin phosphatase target subunit 1; MLC, myosin light chain; LIMK, LIM kinase