Figure 10. Possible mechanisms of HTLV-1 Tax trans-activation.

Figure 10

Possible mechanisms of HTLV-1 Tax trans-activation. The HTLV-1 Tax trans-activator activates HTLV-1 transcription through the Tax response elements (21-bp repeats, TRE) in the U3 region of the HTLV-1 LTR. The TRE binds dimers of CREB/ATF-related proteins, members of the bZIP structural family of transcription factors, through their basic region. Binding of Tax to bZIP proteins enhances dimer formation and DNA-binding activity as well as altering the sequence specificity of DNA binding, resulting in activation of transcription by the bound bZIP proteins. Tax has also been proposed to activate transcription by interacting with coactivators such as CBP and p300 or by directly interacting with basal transcription factors in the RNA polymerase II initiation complex.

From: Transcription

Cover of Retroviruses
Coffin JM, Hughes SH, Varmus HE, editors.
Cold Spring Harbor (NY): Cold Spring Harbor Laboratory Press; 1997.
Copyright © 1997, Cold Spring Harbor Laboratory Press.

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