We know much about HIV transcription and replication. During the past two decades, the roles played by basal transcription complexes, NF-kB and Tat in initiation and elongation of viral transcription have been placed on solid scientific foundation. In addition, the co-activator of NF-kB and the viral transactivator Tat, the positive transcription elongation factor b (P-TEFb), has been demonstrated to phosphorylate the C-terminal domain (CTD) of RNA polymerase II (RNAPII), Spt5 from DSIF and RD from NELF, thus allowing transcription complexes to elongate. P-TEFb itself is under exquisite control in cells, which determines their state of differentiation and proliferation. At least three additional cyclin dependent kinases play a critical role in co- transcriptional processing of HIV RNA, namely Cdk11, 12 and 13, some of which affect 3'end formation (Cdk11) and others the complex splicing of viral transcripts (Cdk12/Cdk13). Recently, we found that the latter two bind CycK, which was thought previously to be another component of P-TEFb. Importantly, CycK does not bind Cdk9, which together with CycT1 or CycT2 forms P-TEFb. This proposal will address in intricate detail how Tat interferes with the formation of inactive P-TEFb complexes in cells, how certain inhibitors of histone deacetylases do the same and how these new CycK complexes affect the splicing of HIV transcripts. In the process, we will have learned how Tat sustains optimal viral replication in infected cells, how drugs such as HMBA, SAHA and specific HDACis perturb the metabolism of P-TEFb and how these new CycK:Cdk complexes affect RNAPII as well as alternative splicing factors. New targets for inhibiting HIV replication will be revealed together with candidate compounds that should find future clinical utility.

Public Health Relevance

Tat transactivation is essential for HIV replication. Tat binds CycT1 and Cdk9 that convert an initiating to an elongating RNA polymerase II. Next, CycK binds Cdk12 and Cdk13 that regulate the co-transcriptional processing of HIV transcripts. This proposal will investigate how Tat uses these complexes for optimal HIV replication and how these Cdks could be manipulated pharmacologically in the future.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI049104-13
Application #
8588278
Study Section
AIDS Molecular and Cellular Biology Study Section (AMCB)
Program Officer
Sharma, Opendra K
Project Start
2001-01-01
Project End
2015-11-30
Budget Start
2013-12-01
Budget End
2014-11-30
Support Year
13
Fiscal Year
2014
Total Cost
$347,625
Indirect Cost
$122,625
Name
University of California San Francisco
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Fujinaga, Koh; Luo, Zeping; Peterlin, B Matija (2014) Genetic analysis of the structure and function of 7SK small nuclear ribonucleoprotein (snRNP) in cells. J Biol Chem 289:21181-90
Liu, Pingyang; Xiang, Yanhui; Fujinaga, Koh et al. (2014) Release of positive transcription elongation factor b (P-TEFb) from 7SK small nuclear ribonucleoprotein (snRNP) activates hexamethylene bisacetamide-inducible protein (HEXIM1) transcription. J Biol Chem 289:9918-25
Peterlin, B Matija; Brogie, John E; Price, David H (2012) 7SK snRNA: a noncoding RNA that plays a major role in regulating eukaryotic transcription. Wiley Interdiscip Rev RNA 3:92-103
Blazek, Dalibor; Kohoutek, Jiri; Bartholomeeusen, Koen et al. (2011) The Cyclin K/Cdk12 complex maintains genomic stability via regulation of expression of DNA damage response genes. Genes Dev 25:2158-72
Contreras, Xavier; Schweneker, Marc; Chen, Ching-Shih et al. (2009) Suberoylanilide hydroxamic acid reactivates HIV from latently infected cells. J Biol Chem 284:6782-9
Chen, Hui; Contreras, Xavier; Yamaguchi, Yuki et al. (2009) Repression of RNA polymerase II elongation in vivo is critically dependent on the C-terminus of Spt5. PLoS One 4:e6918
Li, Qintong; Peterlin, B Matija (2009) Genetic analysis of P-TEFb function via heterologous nucleic acid tethering systems. Methods 48:375-80
Lenasi, Tina; Contreras, Xavier; Peterlin, B Matija (2008) Transcriptional interference antagonizes proviral gene expression to promote HIV latency. Cell Host Microbe 4:123-33
Diaz-Griffero, Felipe; Taube, Ran; Muehlbauer, Stefan M et al. (2008) Efficient production of HIV-1 viral-like particles in mouse cells. Biochem Biophys Res Commun 368:463-9
Contreras, Xavier; Barboric, Matjaz; Lenasi, Tina et al. (2007) HMBA releases P-TEFb from HEXIM1 and 7SK snRNA via PI3K/Akt and activates HIV transcription. PLoS Pathog 3:1459-69

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