Structural Basis for the Regulation of the Mitogen-activated Protein (MAP) Kinase p38α by the Dual Specificity Phosphatase 16 MAP Kinase Binding Domain in Solution

Abstract

Background: Dual specificity phosphatases play a crucial role in MAP kinase regulation. Results: DUSP16 (MKP7) and p38␣ interact in a unique manner that is different from other DUSPs. Conclusion: DUSP16 binds p38␣ via an extended binding surface that includes helix ␣4. Significance: This study shows that DUSPs interact differently with p38␣ and lays the structural basis for their differential regulation of MAPKs.

Molecular basis of MAP kinase regulation

“…There was no detectable binding of these p38 and ERK specific peptides to JNK. Indeed, we have observed the same behavior of KIM peptides/proteins using ITC; i.e., the discrimination factor of DUSP16/MKP7 (a p38/JNK specific DUSP) for p38 versus ERK is only 0.7 . Our unpublished ITC data shows that this behavior is consistent between the majority of p38 and ERK binding proteins.…”

“…Thus far, the interactions between MAPKs (p38, pTpY‐ p38 and ERK2) and MAPK scaffolds (Ets‐1, PEA‐15), kinases (MKK3b, STE7), substrates (ELK1, MBP), and phosphatases (HEPTP, STEP, PTPSL, DUSP16/MKP7) have been studied using these techniques and have allowed us to determine additional structures of full MAPK:MAPK regulatory protein complexes, which are providing new and unexpected insights into MAPK selectivity not only at the KIM binding pocket, but especially at binding pockets outside of it [Fig. (B), p38 complexes; Fig.…”

“…That is, KIM‐motif residues that do not bind directly to the KIM‐motif binding pocket contribute directly to the affinity and specificity of MAPK:KIMpeptide interactions. Furthermore, in the case of the MAPK‐binding domains of DUSP10/MKP5 and DUSP16/MKP7, which share a core interaction motif, binding of additional structural elements of DUSP16/MKP7 lead to an extended interaction surface and thus stronger binding . These MAPK:KIM‐peptide structures have not only revealed that the KIM binding pocket of p38, ERK, and potentially other MAPKs, is bi‐directional binding competent but has also shown how both linear and structured domains engage the KIM binding groove and revealed the importance of intervening residues in the KIM in MAPK selectivity.…”

“…While X‐ray crystallography has provided essential insights into the regulation of MAPKs by their interacting proteins, over the last ∼10 years biomolecular NMR spectroscopy has also been used to complement and critically expand these efforts (Table ) . This contribution was accelerated by new protein labeling techniques, new, more sensitive NMR spectrometers as well as novel NMR techniques .…”

“…Most recently, we showed that while the interaction between the DUSP16/MKP7 MKBD with p38 also binds in a similar mostly C‐to‐N direction, it is also different from that of DUSP6 and DUSP10/MKP5, as it includes not only helix α2 and α3 (largely identical to the interaction of DUSP10/MKP5 MKBD) but also helix α4 [Figs. (C), (B)] . Thus, with these additional structures, it is becoming apparent that while the overall interactions of DUSP/MKP MKBDs with MAPKs are somewhat structurally conserved, there is significant fine tuning, i.e.…”