Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B delta isoform (Ppp2r2d)

B regulatory subunit of protein phosphatase 2A (PP2A) that plays an integral role in cell cycle by controlling mitosis entrance and exit. The activity of PP2A complexes comprising PPP2R2D (PR55- delta) fluctuate during the cell cycle: the activity is high in interphase and low in mitosis.

During mitosis, activity of PP2A is inhibited via interaction with phosphorylated ENSA and ARPP19 inhibitors. Within the PP2A complexes, the B regulatory subunits modulate substrate selectivity and catalytic activity, and also may direct the localization of the catalytic enzyme to a particular subcellular compartment (By similarity).