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. 2018 Mar 22;6:30. doi: 10.3389/fcell.2018.00030

Figure 2.

Figure 2

Protein kinases and protein phosphatases regulate each other during mitosis. Protein kinases and protein phosphatases coordinate with each other through underlying dynamic phosphorylation changes within kinase/phosphatase catalytic or regulatory subunits. Cdk1/cyclin B, directly or indirectly, inhibits the phosphatase activity of PP1, PP2A-B55, and PP4. Conversely, PP1 suppresses the kinase activity of AURKB through its regulatory protein Sds22 (PPP1R7), Plk1 through Mypt1 (PPP1R12A) and Gwl through PPP1R3B. Phosphorylation by Cdk1/cyclin B within or near the PP2A-B56 binding LxxIxE motif in substrates increases the affinity of PP2A-B56 interactions. PP2A-B55 activity is inhibited during mitosis by Gwl phosphorylation of the inhibitory proteins ENSA and ARPP-19. PP1 inactivates Gwl at mitotic exit, thereby activating PP2A-B55. PP6 is the T-loop phosphatase for AURKA, thereby decreasing its activity directly.