HIV trans-activator of transcription protein (HIV Tat)

HIV trans-activator of transcription (Tat) is a small, regulatory protein essential for HIV replication and pathogenesis. It consists of 86–104 amino acids, encoded by two exons, and is characterized by an intrinsically disordered, highly flexible structure allowing multiple protein and RNA interactions[3][5][6][7]. The canonical function of Tat is to dramatically increase the efficiency of transcription of the HIV genome by binding to the trans-activation response (TAR) element in viral RNA and recruiting the host cell positive transcription elongation factor, P-TEFb (CDK9/cyclin T1), to the nascent transcript[1][2][4][9]. Tat’s activity stimulates the production of full-length viral mRNA, facilitating productive HIV infection[1][3][7]. Beyond its nuclear role, Tat is actively secreted by infected cells and can be internalized by bystander cells, contributing to HIV-associated neurotoxicity and immune dysregulation[3]. Tat has proven a difficult therapeutic target due to its structural flexibility, multifunctionality, and sequence variability, but remains of significant interest for new antiviral strategies[2][4][7].

Other names

Tat proteinHIV-1 Tattransactivator of transcriptionHuman Immunodeficiency Virus Tat

Inhibition of Tat-TAR RNA interaction; Inhibition of Tat-P-TEFb complex formation; Blocking Tat-mediated transcriptional activation; Destabilization or degradation of Tat protein