SCAPER_N is a short highly conserved region close to the N-terminus. SCAPER is localised to the endoplasmic reticulum and is a substrate for cyclin A/Cdk2. It associates with cyclin A and localises to the ER. One theory suggests that SCAPER functions to create a local high concentration of cyclin A2 in the cytoplasm. Alternatively, SCAPER might be acting to sequester a portion of cellular cyclin A2 that could then be readily available for nuclear translocation, which may be needed for exit from G0 phase.

1: SCAPER, a novel cyclin A-interacting protein that regulates cell cycle progression. Tsang WY, Wang L, Chen Z, Sanchez I, Dynlacht BD; J Cell Biol. 2007;178:621-633. PMID:17698606

2: The endoplasmic reticulum takes center stage in cell cycle regulation. Fearon P, Cohen-Fix O; Sci Signal. 2008;1:pe4. PMID:18272469