A stable association with PME‐1 may be dispensable for PP2A demethylation – implications for the detection of PP2A methylation and immunoprecipitation

Autor: Ryotaro Yabe, Shunya Tsuji, Satoru Mochida, Tsuyoshi Ikehara, Tatsuya Usui, Takashi Ohama, Koichi Sato
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: FEBS Open Bio, Vol 8, Iss 9, Pp 1486-1496 (2018)
Druh dokumentu: article
ISSN: 2211-5463
DOI: 10.1002/2211-5463.12485
Popis: Reversible methyl‐esterification (methylation) of Leu309 in the protein phosphatase 2A catalytic subunit (PP2Ac) is essential for proper biogenesis of the PP2A holoenzyme. Accumulating evidence links PP2Ac methylation to diseases, including cancer and neurodegenerative disorders. Protein phosphatase methyl‐esterase (PME‐1) specifically catalyzes PP2Ac demethylation. We demonstrate that PP2Ac is demethylated in cell extracts even at 0 °C unless prevented by a PME‐1 methyl‐esterase inhibitor. This promotes dissociation of PP2A heterotrimers with B55 or PR72 subunits, but not those with B56 subunits. These results reveal differential sensitivity of ABC heterotrimers to methylation status of the C subunit. Our study advocates caution when interpreting earlier findings, offers an effective protocol for preserving PP2A complexes, and reveals key distinctions between B subunits and their interactions with the AC core dimer of PP2A.
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