IDENTIFICATION OF A NOVEL CELL-TYPE AND CONTEXT-SPECIFIC ENHANCER WITHIN THE NEGATIVE REGULATORY ELEMENT OF THE HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 LONG TERMINAL REPEAT
Sk. Sikder et al., IDENTIFICATION OF A NOVEL CELL-TYPE AND CONTEXT-SPECIFIC ENHANCER WITHIN THE NEGATIVE REGULATORY ELEMENT OF THE HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 LONG TERMINAL REPEAT, Archives of virology, 137(1-2), 1994, pp. 139-147
One segment of the negative regulatory region of the human immunodefic
iency virus long terminal repeat (HIV-LTR), nucleotides -273 to -255,
is homologous to positive response elements for interleukin-2 and gluc
ocorticoids. We demonstrate that this sequence, referred to as purine-
rich response element (PRRE), acts as a classic enhancer in the contex
t of a heterologous promoter, but serves as a functional repressor in
the intact provirus, binding (a) cellular factor(s). These data sugges
t that certain DNA response elements in the HIV LTR serve as negative
regulators only in the context of the intact LTR, presumably through i
nteractions with other transcriptional factors, a phenomenon that migh
t be exploited to interfere with viral gene transcription.