Catalytic activation of mitogen-activated protein (MAP) kinase phosphatase-1 by binding to p38 MAP kinase: critical role of the p38 C-terminal domain in its negative regulation

Abstract

Mitogen-activated protein (MAP) kinase phosphatase-1 (MKP-1) is the archetypal member of the dual-specificity protein phosphatase family, the expression of which can be rapidly induced by a variety of growth factors and cellular stress. Since MKP-1 protein localizes in the nucleus, it has been suggested to play an important role in the feedback control of MAP kinase-regulated gene transcription. Recently it has been demonstrated that the interaction of several cytosolic MAP kinase phosphatases with MAP kinases can trigger the catalytic activation of the phosphatases. It is unclear whether such a regulatory mechanism can apply to nuclear MAP kinase phosphatases and serve as an additional apparatus for the feedback control of MAP kinase-mediated gene expression. Here we have shown that MKP-1 associates directly with p38 MAP kinase both in vivo and in vitro, and that this interaction enhances the catalytic activity of MKP-1. The point mutation Asp-316-->Asn in the C-terminus of p38, analogous to the ERK2 (extracellular-signal-regulated kinase 2) sevenmaker mutation, dramatically decreases its binding to MKP-1 and substantially compromises its stimulatory effect on the catalytic activity of this phosphatase. Consistent with its defective interaction with MKP-1, this p38 mutant also displays greater resistance to dephosphorylation by the phosphatase. Our studies provide the first example of catalytic activation of a nuclear MAP kinase phosphatase through direct binding to a MAP kinase, suggesting that such a regulatory mechanism may play an important role in the feedback control of MAP kinase signalling in the nuclear compartment.

Heat shock inhibition of lipopolysaccharide-mediated tumor necrosis factor expression is associated with nuclear induction of MKP-1 and inhibition of mitogen-activated protein kinase activation

“…No signal was observed with anti-ERK immunoprecipitation followed by immunoblotting with anti-MKP-1 (data not shown); however, we cannot exclude technical limitations as a confounding factor in these experiments. These data supported the conclusion that MKP-1 physically associates with p38 in the nucleus and, thus, is likely negatively regulating its activity via targeted dephosphorylation consistent with prior observations (25).…”

“…Both blots are representative of two separate experiments. this interaction to be mediated by the C-terminal domain of p38 (25). This report demonstrated that although MKP-1 could regulate p38, induction of MKP-1 dephosphorylation activity was also dependent on interaction with p38 supporting a coregulatory hypothesis (25).…”

Dual-specificity phosphatase DUSP1 protects overactivation of hypoxia-inducible factor 1 through inactivating ERK MAPK

“…In a number of systems, it has been demonstrated that the induction of MKP-1 is concomitant with the inactivation of ERK. Moreover, both in vitro and in vivo MKP-1 is able to efficiently inhibit ERK activity [19,45,46]. Here, we observed that down-regulation of MKP-1 led to an increase in ERK phosphorylation, whereas overexpression of MKP-1 had the reverse effect.…”

Dexamethasone-induced cardioprotection: A role for the phosphatase MKP-1?

“…A similar induction of MKP-1 expression at the promoter level was seen in mast cells and fibroblasts treated with glucocorticoids (Kassel et al 2001). A combination of in vitro and overexpression studies in cultured cells demonstrated that MKP-1 dephosphorylated the MAPK's with the rank order of p38 MAPK N JNK N ERK (Theodosiou et al 1999;Tanoue et al 1999;Hutter et al 2000). In turn, MKP-1 may be catalytically activated by p38 MAPK (Hutter et al 2000), suggesting a complex feed back loop.…”

“…A combination of in vitro and overexpression studies in cultured cells demonstrated that MKP-1 dephosphorylated the MAPK's with the rank order of p38 MAPK N JNK N ERK (Theodosiou et al 1999;Tanoue et al 1999;Hutter et al 2000). In turn, MKP-1 may be catalytically activated by p38 MAPK (Hutter et al 2000), suggesting a complex feed back loop. A suppression of the mitogen activated protein kinase cascade (e.g.…”