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Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells
Published on: January 30, 2019
Human immunodeficiency virus type-1 reverse transcriptase exists as post-translationally modified forms in virions
Adam J Davis1, Jillian M Carr, Christopher J Bagley
1Infectious Diseases Laboratories, SA Pathology, Adelaide 5000, Australia. adam.davis@adelaide.edu.au
Retrovirology
|December 19, 2008
Summary
Post-translational modifications of human immunodeficiency virus type 1 reverse transcriptase (RT) subunits were detected in virions and infected cells. These modifications may regulate RT function within the cell.
Area of Science:
- Biochemistry
- Virology
- Molecular Biology
Background:
- HIV-1 reverse transcriptase (RT) is a key enzyme for viral replication, composed of p66 and p51 subunits.
- Post-translational modifications of RT may regulate its enzymatic activity.
- Understanding RT modifications is crucial for developing antiviral strategies.
Purpose of the Study:
- To detect and characterize different isoforms of HIV-1 RT subunits (p66 and p51) in virions and infected cells.
- To investigate the nature and functional relevance of observed RT post-translational modifications.
Main Methods:
- Two-dimensional (2D) gel electrophoresis was employed to separate and visualize RT isoforms.
- Isoelectric focusing (pI) values were determined for different RT isoforms.
- Phosphatase treatment was used to assess the role of phosphorylation in RT modifications.
Main Results:
- Major p66 and p51 RT isoforms with distinct pI values were identified in virions, infected cells, and reverse transcription complexes (RTCs).
- Observed pI values indicated that most RT in virions and cells is post-translationally modified, differing from theoretical unmodified RT.
- Modifications were selective for each subunit, and some modifications were attributed to phosphorylation, although dephosphorylation did not affect in vitro RT activity.
Conclusions:
- Consistent major p66 and p51 RT isoforms are present in virions, infected cells, and RTCs.
- Both RT subunits undergo post-translational modifications, suggesting a regulatory role within the cell.
- While phosphorylation is implicated, its direct impact on in vitro RT activity appears minimal.
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