Cell cycle regulator. Localizes to the cell membrane of epithelial cells. Its subcellular localization dynamically changes during cell-cycle progression. At the prophase, it concentrates at the nucleoplasm. In the metaphase cells, it becomes diffusive in the cytoplasm and some is concentrated at the mitotic spindles and spindle poles. Expressed in the central nervous system and at different stages of gametogenesis. In embryos, it is expressed in central nervous system and brain. In testis, it is strongly expressed in pre-meiotic germ cells, but is not found in somatic or post-meiotic cells. Predominantly expressed in embryos and in the adult germline (at protein level). Only present in mitotic cells; at the anaphase and telophase, its begins to degrade. Belongs to the SAPAP family.