The oncoprotein Bcl-3 directly transactivates through κB motifs via association with DNA-binding p50B homodimers
V Bours, G Franzoso, V Azarenko, S Park, T Kanno… - Cell, 1993 - cell.com
V Bours, G Franzoso, V Azarenko, S Park, T Kanno, K Brown, U Siebenlist
Cell, 1993•cell.comBcl-3 is an IκB-related protein with ankyrin repeat motifs. Its gene is located at a site of
recurrent translocations in a subset of B cell chronic lymphocytic leukemias. Bcl-3 associates
tightly with p50B (NFKB2, p52) homodimers in cells, and together these proteins form a
ternary complex with DNA at κB sites. Such an association functionally leads to a novel and
potent form of transactivation through the κB motif: the tethering of Bcl-3 to DNA via the p50B
homodimers allows Bcl-3 to transactivate directly, while p50B homodimers alone cannot …
recurrent translocations in a subset of B cell chronic lymphocytic leukemias. Bcl-3 associates
tightly with p50B (NFKB2, p52) homodimers in cells, and together these proteins form a
ternary complex with DNA at κB sites. Such an association functionally leads to a novel and
potent form of transactivation through the κB motif: the tethering of Bcl-3 to DNA via the p50B
homodimers allows Bcl-3 to transactivate directly, while p50B homodimers alone cannot …
Abstract
Bcl-3 is an IκB-related protein with ankyrin repeat motifs. Its gene is located at a site of recurrent translocations in a subset of B cell chronic lymphocytic leukemias. Bcl-3 associates tightly with p50B (NFKB2, p52) homodimers in cells, and together these proteins form a ternary complex with DNA at κB sites. Such an association functionally leads to a novel and potent form of transactivation through the κB motif: the tethering of Bcl-3 to DNA via the p50B homodimers allows Bcl-3 to transactivate directly, while p50B homodimers alone cannot. Transactivation mediated by Bcl-3 requires two cooperating domains located amino- and carboxyterminal to the ankyrin domain. Bcl-3 is localized to the nucleus, and a Bcl-3-p50B complex is detected in certain lymphoid cells. Our data reveal a novel role for Bcl-3, distinct from that of the inhibitor IκB. The results have implications for tumorigenesis.
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