Water channel activity of putative aquaporin-6 present in Aedes aegypti

Abstract

Aquaporins (AQPs) are integral membrane channels that facilitate the bidirectional transport of water and sometimes other small solutes across biological membranes. AQPs are important in mediating environmental adaptations in mosquitoes and are considered as a novel target for the development of effective insecticides against mosquitoes. Here, we expressed Aedes aegypti AQP6 (AaAQP6) in human embryonic kidney (HEK) 293 cells and analyzed the water permeability by a conventional swelling assay, that is, a real-time change in cell size corresponding to the cell swelling induced by hyposmotic solution. The swelling assay revealed that AaAQP6 is a mercury-sensitive water channel. Gene expression studies showed that AaAQP6 is highly expressed in the pupae than other developmental stages. Heterologous expression of AaAQP6 in HEK cell was mainly observed intracellularly suggesting AaAQP6 possibly could be a subcellular water channel and may play an osmoregulatory function in the pupae of A. aegypti.