Figure 6. Model of nNOS mediated S-nitrosylation of H-Ras and inhibition of ERK1/2 activation.

Upon activation of nNOS by calcium influx through the plasma membrane (PM), increased NO^• levels can lead to S-nitrosylation of proximal proteins such as H-Ras. S-nitrosylation of H-Ras on Cys¹¹⁸ may diminish H-Ras activation of Raf-1, possibly by affecting the interactions between a RBD on Raf-1, which is adjacent to GTP binding site and Cys¹¹⁸ of H-Ras. The structure of H-Ras and the RBD was previously reported by Zeng et al. [50] and adapted to this model.