The
HIVtrans-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,
IER3,[4]CDK9, and
Bim.[5]
Human polyomavirus 2 (
JC virus) contains a TAR-homologous sequence in its late promoter[6] that is responsive to HIV-1 derived Tat.[7][8]
References
^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. 50 (22): 5042–5057.
doi:
10.1021/bi200495d.
PMID21553929.