Purification and characterization of the arylphorin gene specific binding protein from an embryonic cell line of Sarcophaga peregrina (flesh fly)

Previously, we purified a DNA binding protein from a nuclear extract of the fat body of Sarcophaga peregrina larvae that binds to the ACCACAACA motif in the 5'-upstream region of the arylphorin gene, and suggested that this protein is a transcriptional activator of the arylphorin gene. In this study, we detected and purified the same protein (ABP-1) from an embryonic cell line of Sarcophaga that does not express the arylphorin gene. Unlike the fat body, which synthesizes arylphorin actively, the embryonic cells were found to contain an additional DNA binding protein (ABP-2) that bound to the same DNA probe as ABP-1, suggesting a novel mechanism of regulation of the arylphorin gene.