Abstract
Post-transcriptional regulation of HIV-1 gene expression is mediated by interactions between viral transcripts and viral/cellular proteins. For HIV-1, post-transcriptional nuclear control allows for the export of intron-containing RNAs which are normally retained in the nucleus. Specific signals on the viral RNAs, such as instability sequences (INS) and Rev responsive element (RRE), are binding sites for viral and cellular factors that serve to regulate RNA-export. The HIV-1 encoded viral Rev protein binds to the RRE found on unspliced and incompletely spliced viral RNAs. Binding by Rev directs the export of these RNAs from the nucleus to the cytoplasm. Previously, Rev co-factors have been found to include cellular factors such as CRM1, DDX3, PIMT and others. In this work, the nuclear matrix protein Matrin 3 is shown to bind Rev/RRE-containing viral RNA. This binding interaction stabilizes unspliced and partially spliced HIV-1 transcripts leading to increased cytoplasmic expression of these viral RNAs.
Highlights
The nucleus is a highly organized structure
Matrin 3 enhances Rev/Rev responsive element (RRE) directed gene expression We identified Matrin 3 as a PTB-1 interacting protein in a yeast 2 hybrid assay (Table 1)
To explore a role for Matrin 3 in HIV-1 replication, we measured the effect of over expressed Matrin 3 on viral Tat and Rev mediated gene expression
Summary
The nucleus is a highly organized structure. Chromosomes occupy discrete regions, and specific proteins and nucleic acids are enriched in subnuclear structures such as nuclear lamina, nucleoli, Cajal bodies, nuclear speckles, and paraspeckles [1,2,3,4,5,6]. Matrin 3 is a highly conserved inner nuclear matrix protein which has been previously shown to play a role in transcription [49,50,51,52]. It interacts with other nuclear matrix proteins to form the internal fibrogranular network; it acts in the nuclear retention of promiscuously A-to-I edited RNAs in cooperation with p54(nrb) and PSF [53,54]; it participates in NMDA-induced neuronal death; it modulates the promoter activity of genes proximal to matrix/scaffold attachment region (MAR/SAR) [55]; and it is involved in the repair of double strand breaks [56].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
