May activate transcription. Required for nuclear translocation of FLOT1. Promotes cell proliferation. May interact with CREBBP. Interacts with FLOT1. Translocates from the cytoplasm to the nucleus at the onset of S-phase. Also localizes to lipid rafts. Ubiquitinated by the CRL2(KLHDC2) complex, which recognizes the diglycine (Gly-Gly) at the C-terminus, leading to its degradation. Ubiquitinated by the CRL2(APPBP2) complex, which recognizes the Arg-Xaa-Xaa-Gly sequence at the C-terminus, leading to its degradation. Belongs to the Mediator complex subunit 25 family. PTOV1 subfamily. Despite sequence similarity to MED25, to date this protein has not been identified as a component of the Mediator complex.