Stage-specific detection of a DNA-binding protein for the storage protein gene of Sarcophaga peregrina.

A nuclear extract of fat body prepared from third instar larvae of Sarcophaga peregrina (flesh fly) was found to contain a DNA-binding protein that specifically bound to 5'-upstream region of the storage protein (arylphorin) gene. This protein was found only in larvae harvested 46 h after larval emergence, indicating that its appearance was strictly regulated by the developmental stage of the insect. Since the storage protein gene is actively transcribed in the fat body at this stage, this protein is probably a specific transcription factor for the storage protein gene. DNase I footprinting analysis showed that the nucleotide sequence of the binding site of this protein is ACCACAACA, which is located at residues -247 to -255 upstream of the +1 site. Results indicated that formation of the DNA-protein complex required Zn2+.