Riese J, Yu X, Munnerlyn A, Eresh S, Hsu SC, Grosschedl R, Bienz M. LEF-1, a nuclear factor coordinating signaling inputs from wingless and decapentaplegic.
Cell 1997;
88:777-87. [PMID:
9118221 DOI:
10.1016/s0092-8674(00)81924-8]
[Citation(s) in RCA: 368] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
wingless and decapentaplegic signal during endoderm induction in Drosophila to regulate expression of the homeotic gene Ultrabithorax. Here, we define a minimal wingless response sequence in the midgut enhancer of Ultrabithorax. We show that this sequence is recognized by the murine transcription factor LEF-1 (lymphocyte enhancer binding factor 1) in a ternary complex with armadillo protein, the cytoplasmic target of the wingless signaling pathway. In stable transformants, transcriptional stimulation of the Ultrabithorax enhancer by LEF-1 depends on armadillo. Furthermore, overexpression of LEF-1 bypasses the need for wingless signaling and causes phenotypes in the midgut, notum, and wing that mimic wingless hyperstimulation. Finally, efficient transcriptional stimulation by LEF-1 in the midgut depends also on the decapentaplegic response sequence and is limited spatially by decapentaplegic signaling. Thus, LEF-1 coordinates inputs from multiple positional signals, consistent with its architectural role in regulating the assembly of multiprotein enhancer complexes.
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