Puralpha as a cellular co-factor of Rev/RRE-mediated expression of HIV-1 intron-containing mRNA.
To ensure successful replication, HIV-1 has developed a Rev-mediated RNA transport system that promotes the export of unspliced genomic RNA from nuclei to cytoplasm. This process requires the Rev responsive element (RRE) that is positioned in the viral transcript encoding Env protein, as well as in unspliced and singly spliced viral transcripts. We identified Puralpha, a single-stranded nucleic acid binding protein as a cellular partner for Rev that augments the appearance of unspliced viral RNAs in the cytoplasm. A decrease in the level of Puralpha expression by siRNA diminishes the level of Rev-dependent expression of viral RNA. Through its nucleic acid binding domain, Puralpha exhibits the ability to interact with the multimerization and RBD domains of Rev. Similar to Rev, Puralpha associates with RRE and in the presence of Rev forms a complex with slower electrophoretic mobility than those from Rev:RRE and Puralpha:RRE. The interaction of Puralpha with RRE occurs in the cytoplasm where enhanced association of Rev with RRE is observed. Our data indicate that the partnership of Puralpha with Rev is beneficial for Rev-mediated expression of the HIV-1 genome.
Kaminski
Rafal
R
Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania 19122, USA.
Darbinian
Nune
N
Sawaya
Bassel E
BE
Slonina
Dorota
D
Amini
Shohreh
S
Johnson
Edward M
EM
Rappaport
Jay
J
Khalili
Kamel
K
Darbinyan
Armine
A
D045744:Cell Line, Tumor; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015694:Gene Products, rev / Q000378:metabolism*; D015752:Genes, env; D015497:HIV-1 / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D007438:Introns; D011485:Protein Binding; D012326:RNA Splicing; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D012367:RNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*; D014779:Virus Replication
D004268:DNA-Binding Proteins; D015694:Gene Products, rev; C501130:PURA protein, human; D012333:RNA, Messenger; D012367:RNA, Viral; D014157:Transcription Factors