MKK3-MPK8 and CAMs-MPK8 modules negatively regulates ROS accumulation through controlling expression of the RBOHD gene during wounding. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Activated by threonine and tyrosine phosphorylation (By similarity). Activated by two independent mechanisms, the binding of CAMs in a calcium-dependent manner and the phosphorylation by MAP kinase kinase MKK3. Activated in response to mechanical wounding, hydrogen peroxide and jasmonic acid (JA). Interacts with CAM3, CAM4 AND CAM7 in an calcium-dependent manner. Ubiquitous. The TXY motif contains the threonine and tyrosine residues whose phosphorylation activates the MAP kinases. Dually phosphorylated on Thr-266 and Tyr-268, which activates the enzyme (By similarity). Autophosphorylated. More susceptible to oxidative stress. Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MAP kinase subfamily.