Kaminski Rafal, Darbinian Nune, Sawaya Bassel E, Slonina Dorota, Amini Shohreh, Johnson Edward M, Rappaport Jay, Khalili Kamel, Darbinyan Armine
Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania 19122, USA.
J Cell Biochem. 2008 Mar 1;103(4):1231-45. doi: 10.1002/jcb.21503.
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.
为确保成功复制,HIV-1已开发出一种由Rev介导的RNA转运系统,该系统可促进未剪接的基因组RNA从细胞核输出到细胞质。这一过程需要位于编码Env蛋白的病毒转录本以及未剪接和单剪接病毒转录本中的Rev反应元件(RRE)。我们鉴定出单链核酸结合蛋白Puralpha是Rev的细胞伴侣,它可增加未剪接病毒RNA在细胞质中的出现。通过小干扰RNA(siRNA)降低Puralpha表达水平会减少病毒RNA的Rev依赖性表达水平。Puralpha通过其核酸结合结构域表现出与Rev的多聚化和RBD结构域相互作用的能力。与Rev相似,Puralpha与RRE结合,并在Rev存在的情况下形成一种电泳迁移率比Rev:RRE和Puralpha:RRE复合物更慢的复合物。Puralpha与RRE的相互作用发生在细胞质中,在那里观察到Rev与RRE的结合增强。我们的数据表明,Puralpha与Rev的合作关系有利于Rev介导的HIV-1基因组表达。