RAN Binding Protein 6 (RANBP6)

RANBP6 (Ran-binding protein 6) belongs to the importin beta family and may function in nuclear protein import as a nuclear transport receptor.RANBP5 and RANBP6 are very closely related judging from sequence alignment and ortholog analysis. To draw the evolutionary path of RANBP5 and RANBP6, their exon arrangement was studied. BLAST searches against the Ensembl genome database found that RANBP6 orthologs exist only in mammals. The emergence of RANBP6 may result from the retroposition of RANBP5 gene, which leads to production of a new functional pseudogene with only a single exon. Judging from known RANBP6 orthologs, the retroposition of RANBP6 from ancient RANBP5 may have happened before the divergence of mammals and birds.