Transcriptional control is relevant in the modulation of mosquito ferritinsynthesis by iron

In yellow fever mosquito cells (Aag2 clone), iron treatment induces a three fold increase in ferritin message (fer mRNA) and protein (ferritin) by 16 h . These data contrast with work in mammalian hepatocytes and fibroblasts in which Ser mRNA levels do not change with iron stimulation, but ferritin le vels increase 50-fold. Pretreatment of the Aag2 cells with actinomycin D bl ocks induction of fer mRNA and reduces the ferritin subunit synthesis, sugg esting that iron induction of ferritin subunit synthesis is subjected to tr anscriptional control. A putative iron-regulatory protein has also been ide ntified in cytoplasmic extracts from Aag2 cells.