Heterogenous nuclear ribonucleoprotein Q increases protein expression from HIV-1 Rev-dependent transcripts

Area of Science:

• Molecular Biology
• Virology
• Gene Regulation

Background:

• Heterogenous nuclear ribonucleoproteins (hnRNPs) are crucial regulators of gene expression, including mRNA processing and translation.
• The HIV-1 Rev protein interacts with specific hnRNPs, including hnRNP Q, hinting at their role in HIV-1 gene regulation.

Purpose of the Study:

• To investigate the impact of hnRNP Q on Rev-dependent gene expression in HIV-1.
• To determine if hnRNP Q influences HIV-1 protein production, mRNA levels, or nucleocytoplasmic distribution.

Main Methods:

• Overexpression of hnRNP Q in reporter gene systems and persistently HIV-1 infected HeLa cells.
• Analysis of protein levels using reporter assays and HIV-1 Gag-p24 quantification.
• Assessment of Rev-dependent mRNA levels and nucleocytoplasmic distribution.

Main Results:

• hnRNP Q overexpression significantly increased protein production from Rev-dependent reporter genes in the presence of Rev.
• These increases in protein levels were not associated with changes in reporter mRNA levels or their distribution.
• Similar effects were observed in HIV-1 infected cells, where hnRNP Q boosted Gag-p24 protein levels without affecting viral mRNA.

Conclusions:

• hnRNP Q enhances HIV-1 protein production from Rev-dependent mRNAs.
• The mechanism involves boosting protein synthesis rather than altering mRNA levels or export.
• hnRNP Q represents a potential target for modulating HIV gene expression at the protein production level.