Alternative titles; symbols
HGNC Approved Gene Symbol: IPO5
Cytogenetic location: 13q32.2 Genomic coordinates (GRCh38): 13:97,953,675-98,024,296 (from NCBI)
Nuclear import of proteins is mediated by the karyopherins (see 600685) and other proteins. Karyopherin beta-3 is believed to be a nuclear transport factor involved in the import of ribosomal proteins (Yaseen and Blobel, 1997).
Yaseen and Blobel (1997) found a sequence in the EST database with significant homology to yeast Kap121p/Pse1p, which is involved in protein secretion and the nuclear import of ribosomal and other proteins. They cloned the human homolog from a bone marrow cDNA library. The human gene encodes a 1,097-amino acid polypeptide with a predicted mass of 123 kD, in agreement with the observed size of native karyopherin beta-3. The protein sequence shows 28% identity to yeast Kap121p/Pse1p and 17% identity to human karyopherin beta-1. Yaseen and Blobel (1997) reported that the sequence contains 2 putative binding sites for Ras-related nuclear protein (601179). Using immunofluorescence, Yaseen and Blobel (1997) demonstrated that karyopherin beta-3 is localized mainly to the cytosol and the nucleus, particularly the nuclear rim, in HeLa cells. They showed that karyopherin beta-3 binds to repeat-containing nucleoporins, Ran-GDP, Ran-GTP, and 2 ribosomal proteins.
Yaseen, N. R., Blobel, G. Cloning and characterization of human karyopherin beta 3. Proc. Nat. Acad. Sci. 94: 4451-4456, 1997. [PubMed: 9114010] [Full Text: https://doi.org/10.1073/pnas.94.9.4451]