Nuclear Pore Associated Protein 1 (NPAP1)

By sequencing YAC clones containing a CpG island in the Prader-Willi syndrome (PWS) critical region on chromosome 15, followed by database analysis and PCR and 3-prime RACE of a human testis cDNA library, Farber et al. (2000) cloned C15ORF2. The deduced protein contains 1,156 amino acids. Northern blot analysis detected a 7.5-kb transcript in adult testis, but not in fetal testis or in any other adult or fetal tissues examined. Southern blot analysis detected C15ORF2 in several primates, but not in any other mammalian or avian species examined. The primate sequences share between 97 and 99% identities. Farber et al. (2000) found that a CpG island associated with C15ORF2 was methylated in all tissues tested except for germ cells. Although C15ORF2 maps between the imprinted genes MAGEL2 and SNRPN , they demonstrated that C15ORF2 was biallelically expressed in adult testis.