The B″-family subunits of protein phosphatase 2A are necessary for in-vitro dephosphorylation of the Arabidopsis mechanosensory transcription factor VIP1.

Protein phosphatase 2A (PP2A) B″-family subunits have Ca ²⁺ -binding EF-hand motifs and can bind PP2A substrates. Arabidopsis thaliana PP2A B″-family subunits are encoded by six genes, and bind a transcription factor, VIP1. VIP1 is dephosphorylated and nuclear-localized by hypo-osmotic stress. However, whether PP2A B″-family subunits mediate the VIP1 dephosphorylation is unclear. Here, we show by yeast two-hybrid and in vitro pull down assays that Arabidopsis PP2A B″-family subunits bind Arabidopsis PP2A A (scaffold) subunits. We also show that VIP1 dephosphorylation in vitro can be induced by a PP2A B″-family subunit.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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