The expanding role of Tax in transcription.
The viral transactivator of HTLV-I, Tax, has long been shown to target the earliest steps of transcription by forming quaternary complexes with sequence specific transcription factors and histone-modifying enzymes in the LTR of HTLV-I. However, a new study suggests that Tax preferentially transactivates the 21-bp repeats through CREB1 and not other bZIP proteins. The additional transactivation of Tax-responsive promoters subsequent to initiation is also presented. This result highlights a potentially novel role of Tax following TBP recruitment (i.e. initiation) and may expand the mechanism of Tax transactivation in promoter clearance and transcriptional elongation.
de la Fuente
Cynthia
C
Department of Biochemistry and Molecular Biology, The George Washington University School of Medicine, Washington, DC 20037, USA. bcmclf@gwumc.edu
Kashanchi
Fatah
F
D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism; D016356:Gene Products, tax / Q000378:metabolism*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D020079:Terminal Repeat Sequences; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
C105242:ALYREF protein, human; C115163:CREB1 protein, human; D017362:Cyclic AMP Response Element-Binding Protein; D016356:Gene Products, tax; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D014157:Transcription Factors