Highly expressed in testis, ovary, liver, spleen, brain, kidney, prostate, lung, and heart. Low expression in liver. Detected in embryo at 10.5 dpc. 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 nucleosome assembly protein (NAP) family.