Analysis of MAPK activities using MAPK-specific antibodies.

Phosphorylation of proteins by mitogen-activated protein kinases is central to many cellular processes, including signal transduction after stress encounter. Thus, assays to identify or characterize MAP kinase activities are a key tool for research in this area. While in-gel kinase assays using isotope-labeled ATP are a powerful tool to investigate the general induction of MAPK activities in any organism, alternative methods using phospho-specific MAPK antibodies are now being established for many model organisms. However, both in-gel kinase assay and phospho-specific western blot analysis do not allow for the unambiguous identification of the activated MAPK. To obtain specificity, initial immunoprecipitation purification of the kinase of interest prior to further analysis can be performed.