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.
Department of Biochemistry and Molecular Biology, The George Washington University School of Medicine, Washington, DC 20037, USA. bcmclf@gwumc.edu
Cynthia
C
de la Fuente
Fatah
F
Kashanchi
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