Characterization of RNA aptamers that disrupt the RUNX1-CBFbeta/DNA complex.
The transcription factor RUNX1 (AML1) is an important regulator of haematopoiesis, and an important fusion partner in leukaemic translocations. High-affinity DNA binding by RUNX1 requires the interaction of the RUNX1 Runt-Homology-Domain (RHD) with the core-binding factor beta protein (CBFbeta). To generate novel reagents for in vitro and in vivo studies of RUNX1 function, we have selected high-affinity RNA aptamers against a recombinant RHD-CBFbeta complex. Selection yielded two sequence families, each dominated by a single consensus sequence. Aptamers from each family disrupt DNA binding by the RUNX1 protein in vitro and compete with sequence-specific dsDNA binding. Minimal, high-affinity ( approximately 100-160 nM) active aptamer fragments 28 and 30 nts in length, consisting of simple short stem-loop structures, were then identified. These bind to the RHD subunit and disrupt its interaction with CBFbeta, which is consistent with reduced DNA affinity in the presence of aptamer. These aptamers represent new reagents that target a novel surface on the RHD required to stabilize the recombinant RHD-CBFbeta complex and thus will further aid exploring the functions of this key transcription factor.
Barton
Jenny L
JL
Section of Experimental Haematology, Leeds Institute of Molecular Medicine, St James's University Hospital, Leeds LS9 7TF, UK.
Bunka
David H J
DH
Knowling
Stuart E
SE
Lefevre
Pascal
P
Warren
Alan J
AJ
Bonifer
Constanze
C
Stockley
Peter G
PG
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001665:Binding Sites; D050676:Core Binding Factor Alpha 2 Subunit / Q000037:antagonists & inhibitors*; D050658:Core Binding Factor beta Subunit / Q000378:metabolism*; D004247:DNA / Q000378:metabolism
D052157:Aptamers, Nucleotide; D050676:Core Binding Factor Alpha 2 Subunit; D050658:Core Binding Factor beta Subunit; D004247:DNA