Ferritin Secretion in Aedes aegypti Larval Cells

Abstract

Female mosquitoes lay eggs after the consuming a blood meal. The iron storage protein ferritin could be involved with iron movement among body tissues in insects. Mosquito ferritin is present in hemolymph (blood) and the messages for the heavy and light chain subunits contain secretion signal sequences. These subunits may be targeted to the secretory pathway. We found that Aedes aegypti larval cells (CCL-125) exposed to iron as ferric ammonium citrate (FAC) increased ferritin secretion in a dose-dependent manner. In order to study the secretory pathway of ferritin, we attempted to disrupt the Golgi by treating CCL-125 cells with brefeldin A (BFA) and monensin. Unexpectedly, neither BFA nor monensin inhibits iron-induced ferritin secretion. These data suggest that either CCL-125 cells are highly resistant to these agents or ferritin is secreted independently of the classical ER-Golgi pathway.