title: Human CRM1 augments production of infectious human and feline immunodeficiency viruses from murine cells.
abstract: Productive replication of human immunodeficiency virus type 1 (HIV-1) occurs efficiently only in humans. The posttranscriptional stages of the HIV-1 life cycle proceed poorly in mouse cells, with a resulting defect in viral assembly and release. Previous work has shown that the presence of human chromosome 2 increases HIV-1 production in mouse cells. Recent studies have shown that human chromosome region maintenance 1 (hCRM1) stimulates Gag release from rodent cells. Here we report that expressions of hCRM1 in murine cells resulted in marked increases in the production of infectious HIV-1 and feline immunodeficiency virus (FIV). HIV-1 production was also increased by hSRp40, and a combination of hCRM1 and hSRp40 resulted in a more-than-additive effect on HIV-1 release. In contrast, the overexpression of mouse CRM1 (mCRM1) minimally affected HIV-1 and FIV production and did not antagonize hCRM1. In the presence of hCRM1 there were large increases in the amounts of released capsid, which paralleled the increases in the infectious titers. Consistent with this finding, the ratios of unspliced to spliced HIV-1 mRNAs in mouse cells expressing hCRM1 and SRp40 became similar to those of human cells. Furthermore, imaging of intron-containing FIV RNA showed that hCRM1 increased RNA export to the cytoplasm.By testing chimeras between mCRM1 and hCRM1 and comparing those sequences to feline CRM1, we mapped the functional domain to HEAT (Huntingtin, elongation factor 3, protein phosphatase 2A, and the yeast kinase TOR1) repeats 4A to 9A and a triple point mutant in repeat 9A, which showed a loss of function. Structural analysis suggested that this region of hCRM1 may serve as a binding site for viral or cellular factors to facilitate lentiviral RNA nuclear export.
authors.affiliation: Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Hila
authors.initials: H
authors.lastname: Elinav
authors.forename: Yuanfei
authors.initials: Y
authors.lastname: Wu
authors.forename: Ayse
authors.initials: A
authors.lastname: Coskun
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Hryckiewicz
authors.forename: Iris
authors.initials: I
authors.lastname: Kemler
authors.forename: Yani
authors.initials: Y
authors.lastname: Hu
authors.forename: Hilary
authors.initials: H
authors.lastname: Rogers
authors.forename: Bing
authors.initials: B
authors.lastname: Hao
authors.forename: Choukri
authors.initials: C
authors.lastname: Ben Mamoun
authors.forename: Eric
authors.initials: E
authors.lastname: Poeschla
authors.forename: Richard
authors.initials: R
authors.lastname: Sutton
mesh_terms: D021581:Active Transport, Cell Nucleus; D000483:Alleles; D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D006678:HIV / Q000378:metabolism*; D015658:HIV Infections / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D016089:Immunodeficiency Virus, Feline / Q000378:metabolism*; D007438:Introns; D028884:Karyopherins / Q000378:metabolism / Q000502:physiology*; D016180:Lentivirus Infections / Q000378:metabolism*; D051379:Mice; D008968:Molecular Conformation; D010957:Plasmids / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism / Q000502:physiology*; D012097:Repressor Proteins / Q000378:metabolism; D000068103:Serine-Arginine Splicing Factors; D014162:Transfection; D000097606:Exportin 1 Protein
chemical_list: D018797:Cell Cycle Proteins; D028884:Karyopherins; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins; D000068103:Serine-Arginine Splicing Factors; D000097606:Exportin 1 Protein; C115188:SRSF10 protein, human