Abstract
The accepted pathway of MAPK activation is through a three kinase phosphorelay arrangement. However, as Johnson explains in his Perspective, new work has established an alternative way for a MAPK called p38a to be activated ( Ge et al.). Apparently, a scaffolding protein called TAB1 that is devoid of any known catalytic activity is able to interact with p38a, inducing its autophosphorylation and consequent activation.