Functional analysis of NTF-1, a developmentally regulated Drosophila transcription factor that binds neuronal cis elements.
In an effort to characterize sequence-specific transcription factors that regulate gene expression during Drosophila development, we identified and purified a novel DNA-binding activity (NTF-1). The purified protein consists of several polypeptides that bind selectively to a functionally important cis-control element of the Ultrabithorax (Ubx) promoter and to the neurogenic elements of both the dopa decarboxylase (Ddc) and fushi tarazu (ftz) promoter/enhancer regions. Purified NTF-1 activates transcription in vitro in a binding site-dependent manner through upstream sequences of the Ubx promoter. A cDNA clone encoding the open reading frame of NTF-1 was isolated, and the deduced primary amino acid sequence of NTF-1 includes a glutamine-rich region reminiscent of the transcriptional activation domains found in Sp1 but no recognizable DNA-binding domain. NTF-1 expression is temporally regulated during embryonic development. In addition, in situ hybridization experiments revealed that NTF-1 is transcribed in a spatially restricted pattern in the embryo, with the highest level of expression observed in the epidermis and a subset of cells in the CNS. Expression of the NTF-1 cDNA in mammalian cells yields a protein that displays DNA-binding and transcriptional activities indistinguishable from that of the collection of proteins isolated from Drosophila embryos. These findings suggest that NTF-1 is a member of a family of developmentally regulated transcription factors that may be involved in directing the expression of genes such as Ubx, Ddc, and ftz in neuronal cells.
Dynlacht
B D
BD
Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Attardi
L D
LD
Admon
A
A
Freeman
M
M
Tjian
R
R
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic; D014616:Vaccinia virus / Q000235:genetics
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D014157:Transcription Factors; C062330:grh protein, Drosophila; D004247:DNA