ARS | Publication request: SELECTIVE INTERACTION OF PLANT HOMEODOMAIN PROTEINS MEDIATES HIGH DNA-BINDING AFFINITY

Submitted to: Proceedings of the National Academy of Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 1, 2002
Publication Date: July 1, 2002
Citation: Smith, H.M., Boschke, I., Hake, S.C. 2002. Selective interaction of plant homeodomain proteins mediates high DNA-binding affinity. Proceedings of the National Academy of Sciences, 99(14):9579-9584.

Interpretive Summary: Understanding molecular mechanisms that control cell fate in the shoot apical meristem is a fundamental question in plant development. Genetic and molecular studies demonstrate that maize KNOTTED1 (KN1) of the TALE (3-aa acid loop extension) class of homeodomain (HD) proteins is involved in shoot apical meristem function. We show that KN1 interacts with knotted interacting protein (KIP), a BEL1-like TALE HD protein.

Technical Abstract: Interaction between KN1 and KIP is mediated by conserved domains in the N termini of both proteins. The KN1 DNA-binding sequence, TGACAG(G/C)T, was biochemically identified, and in vitro DNA-binding assays show that individually KN1 and the HD of KIP bind specifically to this motif with low affinity. The KN1-KIP complex, however, binds specifically to this DNA-binding motif with high affinity, indicating that the association of KN1 and KIP may function in transcriptional regulation.