Nuclear Pore Complex Interacting Protein (NPIP)

Whereas 1 or 2 copies of the segment could be found in baboons, there are 9, 17, 15, and 25 to 30 copies in orangutans, gorillas, humans, and chimpanzees, respectively. Within this segment, Johnson et al. (2001) identified the NPIP gene by genomic sequence analysis and yeast 2-hybrid screening.

The deduced 347-amino acid NPIP protein is membrane bound. Immunofluorescence microscopy demonstrated localization of NPIP to the nuclear membrane and colocalization with nucleoporin p62 (NUP62). Johnson et al. (2001) suggested that the existence of genes that have recently (within the last 30 million years) duplicated and have rapidly evolved may account for 5 to 7% of all human sequences, and they may lack definitive orthologs in the genomes of model organisms.