Importin subunit alpha-3 is a protein that in humans is encoded by the KPNA3gene.
The transport of molecules between the nucleus and the cytoplasm in eukaryotic cells is mediated by the nuclear pore complex (NPC) which consists of 60–100 proteins and is probably 120 million daltons in molecular size. Small molecules (up to 70 kD) can pass through the nuclear pore by nonselective diffusion; larger molecules are transported by an active process. Most nuclear proteins contain short basic amino acid sequences known as nuclear localization signals (NLSs). KPNA3, encodes a protein similar to certain nuclear transport proteins of Xenopus and human. The predicted amino acid sequence shows similarity to Xenopus importin, yeast SRP1, and human RCH1 (KPNA2), respectively. The similarities among these proteins suggests that karyopherin alpha-3 may be involved in the nuclear transport system.
^Takeda S, Fujiwara T, Shimizu F, Kawai A, Shinomiya K, Okuno S, Ozaki K, Katagiri T, Shimada Y, Nagata M, Watanabe T, Takaichi A, Kuga Y, Suzuki M, Hishigaki H, Takahashi E, Shin S, Nakamura Y, Hirai Y (Jun 1997). "Isolation and mapping of karyopherin alpha 3 (KPNA3), a human gene that is highly homologous to genes encoding Xenopus importin, yeast SRP1 and human RCH1". Cytogenet Cell Genet. 76 (1–2): 87–93. doi:10.1159/000134521. PMID9154134.
Sharova N, Bukrinskaya A (1991). "p17 and p17-containing gag precursors of input human immunodeficiency virus are transported into the nuclei of infected cells". AIDS Res. Hum. Retroviruses. 7 (3): 303–6. doi:10.1089/aid.1991.7.303. PMID2064827.
Gallay P, Swingler S, Song J, et al. (1995). "HIV nuclear import is governed by the phosphotyrosine-mediated binding of matrix to the core domain of integrase". Cell. 83 (4): 569–76. doi:10.1016/0092-8674(95)90097-7. PMID7585960.
Gallay P, Swingler S, Aiken C, Trono D (1995). "HIV-1 infection of nondividing cells: C-terminal tyrosine phosphorylation of the viral matrix protein is a key regulator". Cell. 80 (3): 379–88. doi:10.1016/0092-8674(95)90488-3. PMID7859280.
Bukrinsky MI, Haggerty S, Dempsey MP, et al. (1993). "A nuclear localization signal within HIV-1 matrix protein that governs infection of non-dividing cells". Nature. 365 (6447): 666–9. doi:10.1038/365666a0. PMID8105392.
Sato A, Yoshimoto J, Isaka Y, et al. (1996). "Evidence for direct association of Vpr and matrix protein p17 within the HIV-1 virion". Virology. 220 (1): 208–12. doi:10.1006/viro.1996.0302. PMID8659115.
Freed EO, Englund G, Maldarelli F, Martin MA (1997). "Phosphorylation of residue 131 of HIV-1 matrix is not required for macrophage infection". Cell. 88 (2): 171–3; discussion 173–4. doi:10.1016/S0092-8674(00)81836-X. PMID9008157.