Involved in mitotic nuclear envelope reassembly by promoting dephosphorylation of baf-1 during mitotic exit. Coordinates the control of baf-1 dephosphorylation by inhibiting VRK1 kinase and promoting dephosphorylation of baf-1 by protein phosphatase 2A (PP2A), thereby facilitating nuclear envelope assembly. It is unclear whether it acts as a real PP2A regulatory subunit or whether it is involved in recruitment of the PP2A complex