Ser/Thr mitogen-activated kinases (MAPKs) play central roles in a plethora of essential regulatory signalling events. Activation of these MAPKs is orchestrated by a linear enzyme cascade. A large variety of phosphatases, including the tyrosine specific phosphatases and dual specificity phosphatases (DUSPs), are playing roles in the timely and spatial deactivation of MAPK kinases. All of the activating and deactivating regulatory proteins bind to MAPKs via a KIM segment (also known as a D-motif). In this project, the interaction of phosphatases with the p38-MAPK will be explored using transferred-NOE, selective methyl labelling of isoleucine, leucine and valine residues of p38 in combination with isotope-edited/isotope-filtered NOESY experiments. We believe that NMR spectroscopy is highly suitable for studying protein-protein interactions for complexes with low affinity such as the p38 complexes with KIM-peptides and with its specific phosphatases. Understanding the interaction between p38 and the KIM motif of phosphatases will be beneficial to understand the regulatory mechanisms for p38 MAPKs at atomic level resolution.