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A Restriction Enzyme Based Cloning Method to Assess the In vitro Replication Capacity of HIV-1 Subtype C Gag-MJ4 Chimeric Viruses
Published on: August 31, 2014
Context-dependent phenotype of a human immunodeficiency virus type 1 nucleocapsid mutation
1Department of Microbiology, College of Physicians and Surgeons, Columbia Univeirsity, New York, New York, 10032, USA.
Journal of Virology
|July 4, 2001
Summary
A specific mutation in human immunodeficiency virus type 1 (HIV-1) nucleocapsid protein affects viral replication differently between strains. This difference is mainly due to an amino acid change at residue 24, impacting RNA packaging.
Area of Science:
- Virology
- Molecular Biology
- Structural Biology
Background:
- The human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) protein is essential for viral replication.
- Specific mutations in the NC protein can significantly alter viral replication efficiency.
- Differences in viral genetic backgrounds can lead to varied responses to the same mutation.
Purpose of the Study:
- To investigate the differential effects of the R10A/K11A nucleocapsid mutation on HIV-1 replication in two distinct proviral clones.
- To identify the key molecular determinants responsible for the observed phenotypic differences.
Main Methods:
- Functional mapping of HIV-1 proviral clones with specific nucleocapsid mutations.
- Comparative analysis of viral replication phenotypes.
- Structural analysis to understand molecular interactions.
Main Results:
- The R10A/K11A nucleocapsid mutation abolished replication in the HIV-1(HXB-2) clone but had minimal effect on HIV-1(NL4-3).
- A nonconservative amino acid change at residue 24 (Threonine in HXB-2, Isoleucine in NL4-3) was identified as the major determinant of this differential phenotype.
- Amino acid substitutions at residue 24 influenced virion RNA packaging efficiency, with hydrophobic Isoleucine enhancing packaging.
Conclusions:
- Residue 24 of the HIV-1 nucleocapsid protein is a critical determinant of the R10A/K11A mutation's effect on viral replication.
- The differential impact of this mutation is mediated by alterations in viral RNA packaging efficiency, influenced by the hydrophobicity of residue 24.
- Structural insights suggest residue 24 interacts with viral RNA stem-loops within a hydrophobic pocket, affecting packaging.
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