Nuclear import of high risk HPV16 E7 oncoprotein is mediated by its zinc-binding domain via hydrophobic interactions with Nup62.
We previously discovered that nuclear import of high risk HPV16 E7 is mediated by a cNLS located within the zinc-binding domain via a pathway that is independent of karyopherins/importins (Angeline et al., 2003; Knapp et al., 2009). In this study we continued our characterization of the cNLS and nuclear import pathway of HPV16 E7. We find that an intact zinc-binding domain is essential for the cNLS function in mediating nuclear import of HPV16 E7. Mutagenesis of cysteine residues to alanine in each of the two CysXXCys motifs involved in zinc-binding changes the nuclear localization of the EGFP-16E7 and 2xEGFP-16E7 mutants. We further discover that a patch of hydrophobic residues, 65LRLCV69, within the zinc-binding domain of HPV16 E7 mediates its nuclear import via hydrophobic interactions with the FG domain of the central channel nucleoporin Nup62.
Biology Department, Boston College, Chestnut Hill, MA 02467, USA.
Jeremy
J
Eberhard
Zeynep
Z
Onder
Junona
J
Moroianu
D021581:Active Transport, Cell Nucleus; D004252:DNA Mutational Analysis; D006367:HeLa Cells; D052162:Human papillomavirus 16 / Q000502:physiology*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008562:Membrane Glycoproteins / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism*; D050725:Papillomavirus E7 Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D014779:Virus Replication; D015032:Zinc / Q000378:metabolism
D008562:Membrane Glycoproteins; D050505:Mutant Proteins; D028861:Nuclear Pore Complex Proteins; D050725:Papillomavirus E7 Proteins; C049312:nuclear pore protein p62; C059731:oncogene protein E7, Human papillomavirus type 16; D015032:Zinc
EGFP; FG nucleoporin; GST; HPV; HPV16 E7 oncoprotein; Human papillomavirus; NES; NLS; NPC; Nuclear localization signal; Nup62; enhanced green fluorescent protein; glutathione-S-transferase; human papillomavirus; nuclear export signal; nuclear localization signal; nuclear pore complex