Sci. STKE, 11 January 2000
Cell Biology Tied into Protein Degradation
The list of key signaling events that are regulated by controlled ubiquitin-dependent degradation of proteins continues to grow. Brondello et al. report that MAP kinase phosphatase-1 (MKP-1), which dephosphorylates and inactivates the p42 and p44 mitogen-activated protein (MAP) kinases, is degraded by the proteasome. The phosphatase itself is a target of the p42 MAPK and p44 MAPK enzymes that it inactivates. This phosphorylation of MKP-1 appears not to regulate its enzymatic activity, but rather to decrease its ubiquitin-dependent degradation. The MAP kinases also increase transcription of the gene encoding MKP-1, thus providing two signals that increase the abundance of MKP-1. Such regulation would appear to limit prolonged activation of the p42 and p44 MAP kinases.
Citation: Tied into Protein Degradation. Sci. STKE 2000, tw8 (2000).
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