A sequence-specific DNA-binding protein that activates fushi tarazu segmentation gene expression.
The Drosophila segmentation gene fushi tarazu (ftz) is expressed at the cellular blastoderm stage in a pattern of seven transverse stripes; the stripes lie out of register with the segmental primordia, spanning alternate segmental boundaries. The zebra element, a 740-bp DNA sequence upstream of the ftz translational start, directs striped expression of lacZ when introduced into the fly genome. We have purified to homogeneity a sequence-specific DNA-binding factor, FTZ-F1, that binds to two sites located within the zebra element and to two sites within the ftz protein-coding sequence. FTZ-F1 DNA-binding activity is first detected in extracts of 1.5- to 4-hr embryos, coincident with the time of ftz expression in stripes; the activity then diminishes before reappearing during late embryo, larval, and adult stages. When one of the FTZ-F1-binding sequences in the zebra element is mutated by 2- or 4-base substitutions, the binding to FTZ-F1 is disrupted in vitro, and the intensity of lacZ expression is reduced in transformed embryos, especially in stripes 1, 2, 3, and 6. The results suggest that FTZ-F1 is a transcriptional activator necessary for the proper expression of the ftz gene.
Ueda
H
H
Laboratory of Biochemistry, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
Sonoda
S
S
Brown
J L
JL
Scott
M P
MP
Wu
C
C
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D051717:Fushi Tarazu Transcription Factors; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins; D007150:Immunohistochemistry; D007301:Insect Hormones / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D007301:Insect Hormones; D014157:Transcription Factors; C497169:ftz protein, Drosophila