title: Simian immunodeficiency virus Vpx is imported into the nucleus via importin alpha-dependent and -independent pathways.
abstract: Vpx protein of human immunodeficiency virus type 2/simian immunodeficiency virus (SIV) has been implicated in the transport of the viral genome into the nuclei of nondividing cells. The mechanism by which Vpx enters the nucleus remains unknown. Here we have identified two distinct noncanonical nuclear localization signals (NLSs) in Vpx of SIV(smPbj1.9) and defined the pathways for its nuclear import. Although nuclear targeting signals identified here are distinct from known nuclear import signals, translocation of Vpx into the nucleus involves the interaction of its N-terminal NLS (amino acids 20 to 40) or C-terminal NLS (amino acids 65 to 75) with importin alpha and, in the latter case, also with importin beta. Collectively, these results suggest that importins interact with Vpx and ensure the effective import of Vpx into the nucleus to support virus replication in nondividing cells.
authors.affiliation: Laboratory of Molecular Virology, Centre for DNA Fingerprinting and Diagnostics (CDFD), ECIL Road, Nacharam, Hyderabad 500 076, India.
authors.forename: Prabhat K
authors.initials: PK
authors.lastname: Singhal
authors.forename: P Rajendra
authors.initials: PR
authors.lastname: Kumar
authors.forename: Malireddi R K Subba
authors.initials: MR
authors.lastname: Rao
authors.forename: Mahesh
authors.initials: M
authors.lastname: Kyasani
authors.forename: Sundarasamy
authors.initials: S
authors.lastname: Mahalingam
mesh_terms: D000818:Animals; D002522:Chlorocebus aethiops; D015302:Simian Immunodeficiency Virus / Q000235:genetics / Q000502:physiology*; D014709:Vero Cells; D054334:Viral Regulatory and Accessory Proteins / Q000737:chemistry / Q000378:metabolism*; D028901:alpha Karyopherins / Q000378:metabolism*
chemical_list: C513059:VPX protein, Simian immunodeficiency virus; D054334:Viral Regulatory and Accessory Proteins; D028901:alpha Karyopherins