Regulates the expression of chorion genes through binding to gene promoter elements identical to those recognized by the GATA family of transcription factors. Isoform 1 may act as a gonad-specific trans-activator while isoform 2 and isoform 3 may serve as ubiquitous transcriptional modulators. Isoform 1 is present in the ovary and the testis, isoform 2 is found in the larval and pupal tissues, while isoform 3 is found only in some pupal tissues. First appears in follicular cells at late vitellogenic stages that is approximately 12 hours prior to the onset of choriogenesis, its accumulation declines at the onset of choriogenesis and is present at lower levels throughout choriogenesis.