Identification of a novel sonic hedgehog response element in the chicken ovalbumin upstream promoter-transcription factor II promoter.
Sonic hedgehog (Shh) is a secreted morphogen that regulates dorso-ventral patterning within the neural tube during embryonic development. It is well established that Shh can induce motor-neuron differentiation that coincides with the appearance of specific motor-neuron markers including chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) and Isl1. However, the mechanism of Shh-induced signaling pathway in vertebrates is not clearly defined. In this report we have identified COUP-TFII as a target gene for Shh. In addition we have used a 1.6-kb region of the COUP-TFII promoter to identify a target element that mediates the Shh-induced activity. Extensive deletions introduced within this region have further enabled us to identify a novel sonic hedgehog response element (ShhRE) in the COUP-TFII promoter. Point mutations introduced within the ShhRE reveal some key nucleotides that are essential for protein(s)-binding activity. Finally, the ShhRE is capable of functioning as a true enhancer element and can mediate Shh-induced transactivation of reporter gene via a heterologous promoter.
Krishnan
V
V
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
Elberg
G
G
Tsai
M J
MJ
Tsai
S Y
SY
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D019556:COS Cells; D051837:COUP Transcription Factor II; D051836:COUP Transcription Factors; D002645:Chickens; D017077:Culture Media, Conditioned; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D053823:Hedgehog Proteins; D017354:Point Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011506:Proteins / Q000378:metabolism*; D011987:Receptors, Steroid; D015398:Signal Transduction / Q000235:genetics*; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D051837:COUP Transcription Factor II; D051836:COUP Transcription Factors; D017077:Culture Media, Conditioned; D004268:DNA-Binding Proteins; D053823:Hedgehog Proteins; D011506:Proteins; D011987:Receptors, Steroid; D015534:Trans-Activators; D014157:Transcription Factors