PU.1 directly regulates retinoic acid-induced expression of RIG-G in leukemia cells.

RIG-G is a retinoic acid- or interferon-induced gene with potential anti-proliferation function. However, the mechanism underlying ATRA-induced RIG-G induction is not completely understood. Here, we demonstrate that ATRA up-regulates the expression of PU.1, which in turn directly binds to the promoter and increases the expression of RIG-G gene. Luciferase reporter assay and electrophoretic mobility shift assay reveal that PU.1 preferentially binds to one of the two putative binding sites on the RIG-G promoter. Moreover, silencing of PU.1 by shRNA markedly inhibited ATRA- but not IFNα-induced expression of RIG-G. These data provide new insight into the mechanism of ATRA-induced RIG-G expression.