title: Mining the human complexome database identifies RBM14 as an XPO1-associated protein involved in HIV-1 Rev function.
abstract: By recruiting the host protein XPO1 (CRM1), the HIV-1 Rev protein mediates the nuclear export of incompletely spliced viral transcripts. We mined data from the recently described human nuclear complexome to identify a host protein, RBM14, which associates with XPO1 and Rev and is involved in Rev function. Using a Rev-dependent p24 reporter plasmid, we found that RBM14 depletion decreased Rev activity and Rev-mediated enhancement of the cytoplasmic levels of unspliced viral transcripts. RBM14 depletion also reduced p24 expression during viral infection, indicating that RBM14 is limiting for Rev function. RBM14 has previously been shown to localize to nuclear paraspeckles, a structure implicated in retaining unspliced HIV-1 transcripts for either Rev-mediated nuclear export or degradation. We found that depletion of NEAT1 RNA, a long noncoding RNA required for paraspeckle integrity, abolished the ability of overexpressed RBM14 to enhance Rev function, indicating the dependence of RBM14 function on paraspeckle integrity. Our study extends the known host cell interactome of Rev and XPO1 and further substantiates a critical role for paraspeckles in the mechanism of action of Rev. Our study also validates the nuclear complexome as a database from which viral cofactors can be mined.
  
  
  OBJECTIVE
  This study mined a database of nuclear protein complexes to identify a cellular protein named RBM14 that is associated with XPO1 (CRM1), a nuclear protein that binds to the HIV-1 Rev protein and mediates nuclear export of incompletely spliced viral RNAs. Functional assays demonstrated that RBM14, a protein found in paraspeckle structures in the nucleus, is involved in HIV-1 Rev function. This study validates the nuclear complexome database as a reference that can be mined to identify viral cofactors.
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Sona
authors.initials: S
authors.lastname: Budhiraja
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Hongbing
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Internal Medicine, University of Texas Health Sciences Center, Houston, Texas, USA.
authors.forename: Jacob
authors.initials: J
authors.lastname: Couturier
authors.affiliation: Department of Biochemistry, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Malovannaya
authors.affiliation: Department of Biochemistry, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Qin
authors.affiliation: Department of Internal Medicine, University of Texas Health Sciences Center, Houston, Texas, USA.
authors.forename: Dorothy E
authors.initials: DE
authors.lastname: Lewis
authors.affiliation: Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA arice@bcm.edu.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Rice
mesh_terms: D021581:Active Transport, Cell Nucleus; D002460:Cell Line; D015497:HIV-1 / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D028884:Karyopherins / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D054321:rev Gene Products, Human Immunodeficiency Virus / Q000378:metabolism*; D000097606:Exportin 1 Protein
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D028884:Karyopherins; D012367:RNA, Viral; D018160:Receptors, Cytoplasmic and Nuclear; D054321:rev Gene Products, Human Immunodeficiency Virus; D000097606:Exportin 1 Protein; C436317:RBM14 protein, human; C514860:rev protein, Human Immunodeficiency Virus-1