title: Pharmacological validation of an inward-rectifier potassium (Kir) channel as an insecticide target in the yellow fever mosquito Aedes aegypti.
abstract: Mosquitoes are important disease vectors that transmit a wide variety of pathogens to humans, including those that cause malaria and dengue fever. Insecticides have traditionally been deployed to control populations of disease-causing mosquitoes, but the emergence of insecticide resistance has severely limited the number of active compounds that are used against mosquitoes. Thus, to improve the control of resistant mosquitoes there is a need to identify new insecticide targets and active compounds for insecticide development. Recently we demonstrated that inward rectifier potassium (Kir) channels and small molecule inhibitors of Kir channels offer promising new molecular targets and active compounds, respectively, for insecticide development. Here we provide pharmacological validation of a specific mosquito Kir channel (AeKir1) in the yellow fever mosquito Aedes aegypti. We show that VU590, a small-molecule inhibitor of mammalian Kir1.1 and Kir7.1 channels, potently inhibits AeKir1 but not another mosquito Kir channel (AeKir2B) in vitro. Moreover, we show that a previously identified inhibitor of AeKir1 (VU573) elicits an unexpected agonistic effect on AeKir2B in vitro. Injection of VU590 into the hemolymph of adult female mosquitoes significantly inhibits their capacity to excrete urine and kills them within 24 h, suggesting a mechanism of action on the excretory system. Importantly, a structurally-related VU590 analog (VU608), which weakly blocks AeKir1 in vitro, has no significant effects on their excretory capacity and does not kill mosquitoes. These observations suggest that the toxic effects of VU590 are associated with its inhibition of AeKir1.
authors: Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, United States of America.
authors: Matthew F
authors: MF
authors: Rouhier
authors: Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America.
authors: Rene
authors: R
authors: Raphemot
authors: Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America; Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America; Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America; Institute for Global Health, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America.
authors: Jerod S
authors: JS
authors: Denton
authors: Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, United States of America.
authors: Peter M
authors: PM
authors: Piermarini
mesh_terms: D000330:Aedes / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D000818:Animals; D002460:Cell Line; D005260:Female; D015870:Gene Expression; D006801:Humans; D020128:Inhibitory Concentration 50; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology*; D009865:Oocytes / Q000378:metabolism; D024661:Potassium Channels, Inwardly Rectifying / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D015004:Yellow Fever / Q000635:transmission; D015005:Yellow fever virus
chemical_list: D007306:Insecticides; D024661:Potassium Channels, Inwardly Rectifying