TFII-I and USF (RBF-2) regulate Ras/MAPK-responsive HIV-1 transcription in T cells.
The HIV-1 long terminal repeat (LTR) is stringently controlled by T cell activation signals, and binds a variety of transcription factors whose activities are regulated downstream of the T cell receptor. One of the most highly conserved cis-elements on the LTR, designated RBEIII, binds the factor RBF-2 which is comprised of a USF-1/USF-2 heterodimer and a co-factor TFII-I. RBF-2 is necessary for transcription from the LTR in response to RAS-MAPK activation through T cell receptor engagement, but is also required for repression of viral expression in unstimulated cells. Considering the defined activities of USF and TFII-I, RBF-2 may be responsible for regulating promoter context by controlling chromatin organisation, thereby coordinating opportunity for transcriptional activation by additional factors bound to the enhancer region.
Sadowski
Ivan
I
Department of Biochemistry and Molecular Biology, University of British Columbia, 2146 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3. sadowski@interchange.ubc.ca
Mitchell
David A
DA
D002450:Cell Communication; D016325:HIV Long Terminal Repeat / Q000235:genetics / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008213:Lymphocyte Activation / Q000502:physiology; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics; D013601:T-Lymphocytes / Q000821:virology*; D019473:Transcription Factors, TFII / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic / Q000235:genetics / Q000502:physiology; D014161:Transduction, Genetic; D051720:Upstream Stimulatory Factors / Q000235:genetics / Q000502:physiology*
D019473:Transcription Factors, TFII; D051720:Upstream Stimulatory Factors; D020929:Mitogen-Activated Protein Kinase Kinases