Related Experiment Video
Updated: Jul 15, 2026
09:38
Identification of Nucleolar Factors During HIV-1 Replication Through Rev Immunoprecipitation and Mass Spectrometry
Published on: June 26, 2019
hnRNP E1 and E2 have distinct roles in modulating HIV-1 gene expression
Kathryn Woolaway1, Kengo Asai, Andrew Emili
1Department of Molecular and Medical Genetics, University of Toronto Toronto, Ontario, Canada. kew@hotmail.co.uk <kew@hotmail.co.uk>
Retrovirology
|April 25, 2007
Summary
Human nuclear ribonucleoprotein E1 (hnRNP E1) modulates HIV-1 RNA processing and expression by interacting with ESS3a. Overexpression of hnRNP E1 reduces viral Rev protein synthesis and may suppress viral RNA translation.
Area of Science:
- Molecular Biology
- Virology
- Gene Regulation
Background:
- Pre-mRNA processing, including capping, splicing, and polyadenylation, is critical for mRNA export and translation.
- Efficient RNA processing is essential for retroviruses like HIV-1 to express viral proteins.
- Both viral and cellular proteins influence RNA processing.
Purpose of the Study:
- To investigate the role of human nuclear ribonucleoprotein E (hnRNP E) family proteins in HIV-1 RNA metabolism and expression.
- To determine how hnRNP E1/E2 interact with HIV-1 RNA and affect viral protein synthesis.
Main Methods:
- Interaction studies between hnRNP E1/E2 and the ESS3a element of HIV-1.
- Modulation of hnRNP E1 expression levels in HIV-1 infected cells.
- Deletion mutagenesis of hnRNP E1 to identify functional domains.
Main Results:
- hnRNP E1/E2 proteins bind to the ESS3a element within the HIV-1 tat/rev exon 3.
- Altering hnRNP E1 expression impacts HIV-1 structural protein synthesis.
- Overexpression of hnRNP E1 decreases Rev protein levels by reducing rev mRNA, and potentially by suppressing viral RNA translation.
- The C-terminal region of hnRNP E1 is essential for reducing Rev expression.
Conclusions:
- hnRNP E1 is a key regulator of HIV-1 RNA metabolism and expression.
- hnRNP E1's interaction with ESS3a and its C-terminal domain are crucial for modulating viral gene expression.
- hnRNP E1 may act as a broad suppressor of HIV-1 RNA translation, beyond its effect on Rev levels.
Related Concept Videos
02:28Leaky Scanning
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...
01:45Regulation of Nuclear Protein Sorting
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
03:18Non-LTR Retrotransposons
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...