Karyopherin alpha 2

From Wikipedia, the free encyclopedia
  (Redirected from KPNA2)
Jump to: navigation, search
Protein KPNA2 PDB 1ejl.png
Available structures
PDB Ortholog search: PDBe RCSB
Aliases KPNA2, IPOA1, QIP2, RCH1, SRP1alpha, Karyopherin alpha 2, SRP1-alpha, karyopherin subunit alpha 2
External IDs MGI: 103561 HomoloGene: 1708 GeneCards: KPNA2
Gene location (Human)
Chromosome 17 (human)
Chr. Chromosome 17 (human)[1]
Chromosome 17 (human)
Genomic location for KPNA2
Genomic location for KPNA2
Band 17q24.2 Start 68,035,519 bp[1]
End 68,046,842 bp[1]
Species Human Mouse
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC) Chr 17: 68.04 – 68.05 Mb Chr 17: 106.99 – 107 Mb
PubMed search [3] [4]
View/Edit Human View/Edit Mouse

Importin subunit alpha-2 is a protein that in humans is encoded by the KPNA2 gene.[5][6]

The import of proteins into the nucleus is a process that involves at least 2 steps. The first is an energy-independent docking of the protein to the nuclear envelope and the second is an energy-dependent translocation through the nuclear pore complex. Imported proteins require a nuclear localization sequence (NLS) which generally consists of a short region of basic amino acids or 2 such regions spaced about 10 amino acids apart. Proteins involved in the first step of nuclear import are members of the alpha importin family of karyopherins such as importin subunit alpha-2. These include the Xenopus protein importin and its yeast homolog, SRP1 (a suppressor of certain temperature-sensitive mutations of RNA polymerase I in Saccharomyces cerevisiae), which bind to the NLS. KPNA2 protein interacts with the NLSs of DNA helicase Q1 and SV40 T antigen and may be involved in the nuclear transport of proteins. KPNA2 also may play a role in V(D)J recombination[7]


Karyopherin alpha 2 has been shown to interact with:


  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000182481 - Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000018362 - Ensembl, May 2017
  3. ^ "Human PubMed Reference:". 
  4. ^ "Mouse PubMed Reference:". 
  5. ^ Cuomo CA, Kirch SA, Gyuris J, Brent R, Oettinger MA (Jun 1994). "Rch1, a protein that specifically interacts with the RAG-1 recombination-activating protein". Proceedings of the National Academy of Sciences of the United States of America. 91 (13): 6156–60. doi:10.1073/pnas.91.13.6156. PMC 44157Freely accessible. PMID 8016130. 
  6. ^ Weis K, Mattaj IW, Lamond AI (May 1995). "Identification of hSRP1 alpha as a functional receptor for nuclear localization sequences". Science. 268 (5213): 1049–53. doi:10.1126/science.7754385. PMID 7754385. 
  7. ^ "Entrez Gene: KPNA2 karyopherin alpha 2 (RAG cohort 1, importin alpha 1)". 
  8. ^ Lin CY, Huang PH, Liao WL, Cheng HJ, Huang CF, Kuo JC, Patton WA, Massenburg D, Moss J, Lee FJ (Dec 2000). "ARL4, an ARF-like protein that is developmentally regulated and localized to nuclei and nucleoli". The Journal of Biological Chemistry. 275 (48): 37815–23. doi:10.1074/jbc.M002470200. PMID 10980193. 
  9. ^ Perez-Villar JJ, O'Day K, Hewgill DH, Nadler SG, Kanner SB (Oct 2001). "Nuclear localization of the tyrosine kinase Itk and interaction of its SH3 domain with karyopherin alpha (Rch1alpha)". International Immunology. 13 (10): 1265–74. doi:10.1093/intimm/13.10.1265. PMID 11581171. 
  10. ^ Nagoshi E, Yoneda Y (Apr 2001). "Dimerization of sterol regulatory element-binding protein 2 via the helix-loop-helix-leucine zipper domain is a prerequisite for its nuclear localization mediated by importin beta". Molecular and Cellular Biology. 21 (8): 2779–89. doi:10.1128/MCB.21.8.2779-2789.2001. PMC 86908Freely accessible. PMID 11283257. 
  11. ^ Köhler M, Speck C, Christiansen M, Bischoff FR, Prehn S, Haller H, Görlich D, Hartmann E (Nov 1999). "Evidence for distinct substrate specificities of importin alpha family members in nuclear protein import". Molecular and Cellular Biology. 19 (11): 7782–91. doi:10.1128/mcb.19.11.7782. PMC 84838Freely accessible. PMID 10523667. 
  12. ^ Kutay U, Bischoff FR, Kostka S, Kraft R, Görlich D (Sep 1997). "Export of importin alpha from the nucleus is mediated by a specific nuclear transport factor". Cell. 90 (6): 1061–71. doi:10.1016/s0092-8674(00)80372-4. PMID 9323134. 
  13. ^ Braem CV, Kas K, Meyen E, Debiec-Rychter M, Van De Ven WJ, Voz ML (May 2002). "Identification of a karyopherin alpha 2 recognition site in PLAG1, which functions as a nuclear localization signal". The Journal of Biological Chemistry. 277 (22): 19673–8. doi:10.1074/jbc.M112112200. PMID 11882654. 
  14. ^ Seki T, Tada S, Katada T, Enomoto T (May 1997). "Cloning of a cDNA encoding a novel importin-alpha homologue, Qip1: discrimination of Qip1 and Rch1 from hSrp1 by their ability to interact with DNA helicase Q1/RecQL". Biochemical and Biophysical Research Communications. 234 (1): 48–53. doi:10.1006/bbrc.1997.6535. PMID 9168958. 
  15. ^ Maiyar AC, Leong ML, Firestone GL (Mar 2003). "Importin-alpha mediates the regulated nuclear targeting of serum- and glucocorticoid-inducible protein kinase (Sgk) by recognition of a nuclear localization signal in the kinase central domain". Molecular Biology of the Cell. 14 (3): 1221–39. doi:10.1091/mbc.E02-03-0170. PMC 151592Freely accessible. PMID 12631736. 

Further reading[edit]