Maertens, GoedeleCherepanov, PeterDebyser, ZegerEngelborghs, YvesEngelman, Alan2019-10-052004Maertens, Goedele, Peter Cherepanov, Zeger Debyser, Yves Engelborghs, and Alan Engelman. 2004. “Identification and Characterization of a Functional Nuclear Localization Signal in the HIV-1 Integrase Interactor LEDGF/p75.” Journal of Biological Chemistry 279 (32): 33421–29. https://doi.org/10.1074/jbc.m404700200.0021-92581083-351Xhttp://nrs.harvard.edu/urn-3:HUL.InstRepos:41482906Human lens epithelium-derived growth factor ( LEDGF)/p75 protein forms a specific nuclear complex with human immunodeficiency virus type 1 (HIV-1) integrase and is essential for nuclear localization and chromosomal association of the viral protein. We now studied nuclear import of LEDGF/p75 in live and semipermeabilized cells. We show that nuclear import of LEDGF/p75 is GTP-, Ran-, importin-alpha/beta-, and energy-dependent and that the protein competes with the canonical SV40 large T antigen nuclear localization signal (NLS) for nuclear import receptors. We identified the NLS of LEDGF/p75 through deletion analysis and site-directed mutagenesis. The LEDGF/p75 NLS, (148)GRKR-KAEKQ(156), belongs to the canonical SV40-like family. Fusion of this short peptide to the amino terminus of Escherichia coli beta-galactosidase rendered the fusion protein nuclear, confirming that the LEDGF/p75 NLS is transferable. Moreover, a single amino acid change in the NLS was sufficient to exclude the mutant LEDGF/ p75 protein from the nucleus and abolish nuclear import of HIV-1 integrase.en-USJournal Article2019-10-0510.1074/jbc.M404700200