Trans-activation response element (TAR)

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Trans-activation response element (TAR)
Predicted secondary structure and sequence conservation of mir-TAR
Symbol mir-TAR
Alt. Symbols TAR
Rfam RF00250
Other data
RNA type Gene; miRNA
Domain(s) Viruses
GO 0035068 0035195
SO 0000233 0001244

The HIV trans-activation response (TAR) element is an RNA element which is known to be required for the trans-activation of the viral promoter and for virus replication. The TAR hairpin is a dynamic structure[1] that acts as a binding site for the Tat protein, and this interaction stimulates the activity of the long terminal repeat promoter.[2]

Further analysis has shown that TAR is a pre-microRNA that produces mature microRNAs from both strands of the TAR stem-loop.[3] These miRNAs are thought to prevent infected cells from undergoing apoptosis by downregulating the genes ERCC1 and IER3.[4]


  1. ^ Lu, Jia; Kadakkuzha, Beena M.; Zhao, Liang et al. (2011). "Dynamic Ensemble View of the Conformational Landscape of HIV-1 TAR RNA and Allosteric Recognition". Biochemistry 22 (50): 5042–5057. doi:10.1021/bi200495d. PMID 21553929. 
  2. ^ Kulinski, T; Olejniczak M; Huthoff H; Bielecki L; Pachulska-Wieczorek K; Das AT; Berkhout B; Adamiak RW (2003). "The apical loop of the HIV-1 TAR RNA hairpin is stabilized by a cross-loop base pair". J Biol Chem 278 (40): 38892–38901. doi:10.1074/jbc.M301939200. PMID 12882959. 
  3. ^ Ouellet DL, Plante I, Landry P et al. (April 2008). "Identification of functional microRNAs released through asymmetrical processing of HIV-1 TAR element". Nucleic Acids Res. 36 (7): 2353–65. doi:10.1093/nar/gkn076. PMC 2367715. PMID 18299284. 
  4. ^ Klase Z, Winograd R, Davis J et al. (2009). "HIV-1 TAR miRNA protects against apoptosis by altering cellular gene expression". Retrovirology 6: 18. doi:10.1186/1742-4690-6-18. PMC 2654423. PMID 19220914. 

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