Members of the E2F family of transcription factors are recognised to
be major regulators of cell cycle and apoptosis in interplaywith binding
partners from the pocket protein family [16], but increasing evidence
also points to their activity outside of this partnership, especially in cellular
differentiation [17]. Since there is very little data on E2F function in
ATP-binding cassette gene regulation and none of it relates to mitochondrialABC
transporter genes,we decided to characterise inmore detail
the crucial role of E2Fs in ABCB10 expression discovered by us.
Within the present study, we identify specific E2F binding sites in the
promoter region of ABCB10 that are responsible for the stimulatory effect
of E2F2, E2F3, and E2F4 as well as partially for the basal activity of
the promoter. Moreover, we show that downregulation of E2F4 significantly
suppresses the expression of human ABCB10 in K562, HepG2 and
HEK293 cells.