Diaz-Griffero Lab

Recent work has suggested a role for Nup98 and Nup153 in HIV-1 replication (Di Nunzio et al., 2012; Konig et al., 2008; Matreyek and Engelman, 2011). Nup98, which is symmetrically localized to the cytoplasmic and nuclear sides of the nuclear pore, is involved in HIV-1 integration (Di Nunzio et al., 2012; Ebina et al., 2004; Konig et al., 2008). Nup153 that localizes to the nuclear side of the nuclear pore, was initially described to be involved in HIV-1 replication by three independent genome-wide siRNA screens (Brass et al., 2008; Konig et al., 2008; Zhou et al., 2008). Although the C terminus domain of Nup153 has been shown to bind the HIV-1 integrase protein using bacterially purified proteins (Woodward et al., 2009), the genetic determinant for the requirement of Nup153 during HIV-1 infection has been mapped to the capsid protein (Matreyek and Engelman, 2011). In agreement with the latter, HIV-1 bearing mutations on capsid showed different infection sensitivities to the depletion of Nup153 (Lee et al., 2010; Matreyek and Engelman, 2011; Schaller et al., 2011).

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We initially confirmed the involvement of Nup98 and Nup153 in the early steps of HIV-1 infection by testing infectivity of Nup98 and Nup153 -depleted Jurkat cells. Nup98-depleted cells modestly block HIV-1 infection during integration. By contrast, Nup-153-depleted cells preferentially block HIV-1 infection during nuclear import. In agreement with findings that showed capsid as the determinant for the requirement of Nup153, we demonstrated the ability of Nup153 to interact with the HIV-1 core. Because depletion of Nup153 affects nuclear import but severely diminishes infectivity, we studied the distribution of HIV-1 integration sites in Nup153-depleted Jurkat cells. Our findings revealed that the intragenic/intergenic ratio of integration sites changes in Nup153-depleted cells.