Molecular biology of insect sodium channels and pyrethroid resistance.
Voltage-gated sodium channels are essential for the initiation and propagation of the action potential in neurons and other excitable cells. Because of their critical roles in electrical signaling, sodium channels are targets of a variety of naturally occurring and synthetic neurotoxins, including several classes of insecticides. This review is intended to provide an update on the molecular biology of insect sodium channels and the molecular mechanism of pyrethroid resistance. Although mammalian and insect sodium channels share fundamental topological and functional properties, most insect species carry only one sodium channel gene, compared to multiple sodium channel genes found in each mammalian species. Recent studies showed that two posttranscriptional mechanisms, alternative splicing and RNA editing, are involved in generating functional diversity of sodium channels in insects. More than 50 sodium channel mutations have been identified to be responsible for or associated with knockdown resistance (kdr) to pyrethroids in various arthropod pests and disease vectors. Elucidation of molecular mechanism of kdr led to the identification of dual receptor sites of pyrethroids on insect sodium channels. Many of the kdr mutations appear to be located within or close to the two receptor sites. The accumulating knowledge of insect sodium channels and their interactions with insecticides provides a foundation for understanding the neurophysiology of sodium channels in vivo and the development of new and safer insecticides for effective control of arthropod pests and human disease vectors.
Department of Entomology, Neuroscience and Genetics Programs, Michigan State University, East Lansing, MI, USA. Electronic address: dongk@msu.edu.
Ke
K
Dong
Department of Entomology, Neuroscience and Genetics Programs, Michigan State University, East Lansing, MI, USA.
Yuzhe
Y
Du
Department of Entomology, Neuroscience and Genetics Programs, Michigan State University, East Lansing, MI, USA.
Frank
F
Rinkevich
Department of Entomology, Neuroscience and Genetics Programs, Michigan State University, East Lansing, MI, USA.
Yoshiko
Y
Nomura
Department of Entomology, Neuroscience and Genetics Programs, Michigan State University, East Lansing, MI, USA.
Peng
P
Xu
Department of Entomology, Neuroscience and Genetics Programs, Michigan State University, East Lansing, MI, USA.
Lingxin
L
Wang
Department of Anatomy and Physiology, Kansas State University, Manhattan, KS, USA.
Kristopher
K
Silver
Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada; Sechenov Institute of Evolutionary Physiology & Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.
Boris S
BS
Zhorov
D017398:Alternative Splicing; D000818:Animals; D007313:Insecta / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D007305:Insecticide Resistance / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology; D011722:Pyrethrins / Q000494:pharmacology*; D017393:RNA Editing; D015222:Sodium Channels / Q000235:genetics* / Q000378:metabolism
D007306:Insecticides; D011722:Pyrethrins; D015222:Sodium Channels
Alternative splicing; Knockdown resistance; Pyrethroid receptor sites; Pyrethroids; RNA editing; Sodium channel