Negative regulation of protein phosphatase 2Cbeta by ISG15 conjugation.
ISG15, an interferon-upregulated ubiquitin-like protein, is covalently conjugated to various cellular proteins (ISGylation). In this study, we found that protein phosphatase 2Cbeta (PP2Cbeta), which functions in the nuclear factor kappaB (NF-kappaB) pathway via dephosphorylation of TGF-beta-activated kinase, was ISGylated, and analysis by NF-kappaB luciferase reporter assay revealed that PP2Cbeta activity was suppressed by co-expression of ISG15, UBE1L, and UbcH8. We determined the ISGylation sites of PP2Cbeta and constructed its ISGylation-resistant mutant. In contrast to the wild type, this mutant suppressed the NF-kappaB pathway even in the presence of ISG15, UBE1L, and UbcH8. Thus, we propose that ISGylation negatively regulates PP2Cbeta activity.
Takeuchi
Tomoharu
T
Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
Kobayashi
Takayasu
T
Tamura
Shinri
S
Yokosawa
Hideyoshi
H
D016207:Cytokines / Q000378:metabolism*; D015536:Down-Regulation; D006367:HeLa Cells; D006801:Humans; D008239:Lysine / Q000378:metabolism; D020930:MAP Kinase Kinase Kinases / Q000037:antagonists & inhibitors; D016328:NF-kappa B / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000737:chemistry / Q000378:metabolism*; D000071636:Protein Phosphatase 2C; D014452:Ubiquitins / Q000378:metabolism*; D000099151:MAP Kinase Kinase Kinase 7
D016207:Cytokines; D008239:Lysine; D020930:MAP Kinase Kinase Kinases; D016328:NF-kappa B; D010749:Phosphoprotein Phosphatases; D000071636:Protein Phosphatase 2C; D014452:Ubiquitins; D000099151:MAP Kinase Kinase Kinase 7