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Functions of Tat: the versatile protein of human immunodeficiency virus type 1

Bizhan Romani1, Susan Engelbrecht, Richard H Glashoff

  • 1Division of Medical Virology, Department of Pathology, University of Stellenbosch, Tygerberg 7505, South Africa. bizhan@sun.ac.za

The Journal of General Virology
|October 9, 2009
PubMed

Human immunodeficiency virus type 1 (HIV-1) Tat is a multifunctional protein that contributes to several pathological symptoms of HIV-1 infection as well as playing a critical role in virus replication. Tat is a robust transactivating protein that induces a variety of effects by altering the expression levels of cellular and viral genes. The functions of Tat are therefore primarily related to its role in modulation of gene expression. In this review the functions of HIV-1 Tat that have been well documented, as well as a number of novel functions that have been proposed for this protein, are discussed. Since some of the functions of Tat vary in different cell types in a concentration-dependent manner and because Tat sometimes exerts the same activity through different pathways, study of this protein has at times yielded conflicting and controversial results. Due to its pivotal role in viral replication and in disease pathogenesis, Tat and the cellular pathways targeted by Tat are potential targets for new anti-HIV drugs.

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