Protein phosphatase 2A‐B56 controls mitosis by interacting with LS/TPI/V motif containing protein interactors

Mitosis, like many other cellular processes, is tightly regulated by reversible protein phosphorylation which is achieved by coordinated activities of mitotic protein kinases and mitotic protein phosphatases. PP2A‐B56 is an important mitotic protein phosphatase which contributes to the timely execution of several mitotic events. Recent proteomic studies show that PP2A‐B56 recognizes a short linear motif, LXXIXE, on its interactors. We hypothesize that LS/TPI/V is a consensus motif for the recruitment of PP2A‐B56 in an isoform‐dependent manner, particularly during mitosis. We also speculate that this motif is phosphorylated during mitosis and dephosphorylated at mitotic exit. Recruitment of PP2A‐B56 is regulated by the phosphorylation status of this motif and this, in turn, plays an important role in controlling the progression of the cell cycle. Our findings show that LS/TPI/V motif is present in more than 100 mitotic regulators and several of them interact with PP2A‐B56 in a phosphorylation‐dependent and isoform‐dependent manner. Further understanding of how interactions between the target proteins and PP2A‐B56 affect mitotic progression and/or mitotic exit will provide valuable insight into the mechanisms of specific recruitment and mitotic functions of PP2A‐B56. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .