Dual phosphorylation of protein phosphatase PPM1H promotes dephosphorylation of Smad1 in cellulo
| Autor: | Misato Nakatani, Noriyuki Sueyoshi, Isamu Kameshita, Saki Ueta, Kazutoshi Akizuki, Yuiko Inui, Akari Kashimura, Yasushi Shigeri, Atsuhiko Ishida, Jin Osawa |
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| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
Calmodulin Phosphatase Biophysics Biochemistry Smad1 Protein Dephosphorylation 03 medical and health sciences chemistry.chemical_compound Mice 0302 clinical medicine Cell Line Tumor Animals Humans Phosphorylation Protein kinase A Molecular Biology Transcription factor biology Chemistry Kinase Cell Biology Cyclic AMP-Dependent Protein Kinases Cell biology 030104 developmental biology HEK293 Cells Calcium-Calmodulin-Dependent Protein Kinase Type 1 030220 oncology & carcinogenesis Ionomycin biology.protein |
| Zdroj: | Biochemical and biophysical research communications. 530(3) |
| ISSN: | 1090-2104 |
| Popis: | Protein phosphatase PPM1H is known to participate in various biological or pathophysiological mechanisms. However, little is known about the molecular mechanisms of its regulation. In this study, we investigated the protein kinases that directly phosphorylate PPM1H, identifying them as cAMP-dependent protein kinase (PKA) and Ca2+/calmodulin-dependent protein kinase I (CaMKI). In vitro and in silico analyses showed that the phosphorylation sites of PPM1H by PKA and CaMKI were Ser-123 and Ser-210, respectively. The phosphorylation state of PPM1H in cells exhibited the kinase activator- and inhibitor-dependent changes. In mouse neuroblastoma Neuro2a cells, phosphorylation of Ser-210 was much higher in the phospho-mimetic mutant (S123D) than in the non-phosphorylatable mutant (S123A) when they were treated with ionomycin. This suggests that a hierarchical phosphorylation, with initial phosphorylation of Ser-123 promoting subsequent phosphorylation of Ser-210, occurs in these neuron-like cells. Moreover, in cell-based assay a PPM1H(S123A/S210A) double mutant barely dephosphorylated Smad1, a transcription factor known as an endogenous substrate of PPM1H. These results suggest that cAMP and Ca2+/calmodulin regulate dephosphorylation of Smad1 through the dual phosphorylation of PPM1H at Ser-123 and Ser-210. |
| Databáze: | OpenAIRE |
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