Regulation of HIV-1 gene expression.
The quantity and quality of HIV-1 gene expression is temporally controlled by a cascade of sequential regulatory interactions. Basal HIV-1 transcription is determined by interaction of cellular regulatory proteins with specific DNA target sequences within the HIV-1 long-terminal repeat. The most notable of these protein:DNA interactions involves NF-kappa B, a transcription factor that plays a pivotal role in the activation of genes important for cellular responses to infection and inflammation. A second level of control involves the virally encoded Tat trans-activator. Tat, in combination with as yet unidentified cellular proteins, activates HIV-1 gene expression through a specific interaction with the viral TAR RNA stem-loop target sequence. A final level of regulation is mediated by the viral Rev protein. Rev acts posttranscriptionally to induce the expression of HIV-1 structural proteins and thereby commits HIV-1 to the late, cytopathic phase of the viral replication cycle. Rev activity appears to require a critical, threshold level of Rev protein expression, thus preventing entry into this late phase in cells that are unable to support efficient HIV-1 gene expression. In total, this cascade of regulatory levels allows the HIV-1 provirus to respond appropriately to the intracellular milieu present in each infected cell. In activated cells, the combination of Tat and Rev can stimulate a very high level of viral gene expression and replication. In quiescent or resting cells, in contrast, these same regulatory proteins are predicted to maintain the HIV-1 provirus in a latent or nonproductive state.
Altmetric Attention Stats
Dimensions Citation Stats
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- vpr Gene Products, Human Immunodeficiency Virus
- vif Gene Products, Human Immunodeficiency Virus
- nef Gene Products, Human Immunodeficiency Virus
- Viral Regulatory and Accessory Proteins
- Transcription, Genetic
- Receptors, Cell Surface
- RNA
- Promoter Regions, Genetic
- NF-kappa B
- Molecular Sequence Data
Citation
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- vpr Gene Products, Human Immunodeficiency Virus
- vif Gene Products, Human Immunodeficiency Virus
- nef Gene Products, Human Immunodeficiency Virus
- Viral Regulatory and Accessory Proteins
- Transcription, Genetic
- Receptors, Cell Surface
- RNA
- Promoter Regions, Genetic
- NF-kappa B
- Molecular Sequence Data