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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
32
pubmed:dateCreated
2000-9-12
pubmed:abstractText
Unlike cellular mRNA, retroviral mRNA bypasses the tight coupling of the splicing and nuclear export steps to allow the export of intron-containing viral RNA transcripts to the cytoplasm. Two distinct nuclear export pathways for retroviral mRNA have been described: a CRM-1 dependent pathway mediated by the HIV-1 Rev protein and the Rev Response Element (RRE), and a CRM-1 independent pathway mediated by the Constitutive Transport Element (CTE) of type D retroviruses. Two CTE-binding proteins, RNA helicase A (RHA) and Tap, have been implicated in the nuclear export of CTE-containing RNA. Recently, we reported that expression of RRE-containing RNA could also be mediated by a cellular protein, Sam68, independently of Rev. Here we report evidence that Sam68, RHA and Tap cooperate in the nuclear export of both CTE- and RRE-containing RNA. RHA binds to Sam68 and to Tap both in vivo and in vitro. Over-expression of Sam68 activates both RRE- and CTE-regulated reporter gene expression in human cells and in quail cells in the presence of human Tap. This activation was competitively inhibited by the nuclear transport domain (NTD) of RHA and a transdominant negative mutant of Tap. Conversely, the activation of CTE by Tap in quail cells was inhibited by a transdominant mutant of Sam68 and NTD. We propose that both HIV and type D retroviruses may access the same constitutive RNA nuclear export pathway involving RHA, Tap and Sam68, even though HIV also utilizes the Rev protein for more efficient nuclear export. it is likely that this constitutive export pathway is also used by cellular mRNA, but at a different interface with the splicing process.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Adaptor Proteins, Signal Transducing, http://linkedlifedata.com/resource/pubmed/chemical/DNA-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/HIV Core Protein p24, http://linkedlifedata.com/resource/pubmed/chemical/KHDRBS1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/NXF1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Nuclear Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Nucleocytoplasmic Transport Proteins, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Viral, http://linkedlifedata.com/resource/pubmed/chemical/RNA Helicases, http://linkedlifedata.com/resource/pubmed/chemical/RNA-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3570-5
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:10951562-Adaptor Proteins, Signal Transducing, pubmed-meshheading:10951562-Betaretrovirus, pubmed-meshheading:10951562-Cell Line, Transformed, pubmed-meshheading:10951562-DNA-Binding Proteins, pubmed-meshheading:10951562-Gene Expression Regulation, Viral, pubmed-meshheading:10951562-HIV Core Protein p24, pubmed-meshheading:10951562-HIV-1, pubmed-meshheading:10951562-HeLa Cells, pubmed-meshheading:10951562-Humans, pubmed-meshheading:10951562-Mutagenesis, pubmed-meshheading:10951562-Nuclear Proteins, pubmed-meshheading:10951562-Nucleocytoplasmic Transport Proteins, pubmed-meshheading:10951562-RNA, Messenger, pubmed-meshheading:10951562-RNA, Viral, pubmed-meshheading:10951562-RNA Helicases, pubmed-meshheading:10951562-RNA Processing, Post-Transcriptional, pubmed-meshheading:10951562-RNA-Binding Proteins, pubmed-meshheading:10951562-Recombinant Fusion Proteins, pubmed-meshheading:10951562-Transcriptional Activation
pubmed:year
2000
pubmed:articleTitle
Sam68, RNA helicase A and Tap cooperate in the post-transcriptional regulation of human immunodeficiency virus and type D retroviral mRNA.
pubmed:affiliation
Department of Medicine, University of California, San Diego, La Jolla 92093-0665, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't