Activation of c-Raf1 by PKC eta in cytosol At the level of Raf, the kinase that phosphorylates MEK-1, the activation cascade diverges; while conventional and novel PKCs (isotypes a and h) are potent activators of c-Raf1, atypical PKC-z cannot increase c-Raf1 activity,stimulating MEK by an independent mechanism. IEV:0001363 IMR:0001150 IMR:0100355 PubMed:9447975 event Activation of Raf-1 by PKC in cytosol