Trimeric Intracellular Cation Channel B Participates In 20-hydroxyecdysone-induced Ca²⁺ Release And Influx

Background and significanceInsects are the largest group of animals.They play important roles in human society in agriculture and medical area.Many recent researches on physiology chose insects as the research material.Molting and metamorphosis are necessary for insects in developing period.Molting is regulated by 20-hydroxyecdysone?20E?and juvenile hormone?JH?.20E triggered the procedure of molting,and JH determined the direction of molting.Previous researches on development established the classic genomic signaling pathway by 20E freely diffusing into the plasma membrane directly.However,recent researches show that some G-protein-coupled receptors?GPCRs?could respond the 20E signal,and induce Ca²⁺ release and influx.Ca²⁺ is stored in endoplasmic reticulum.It releases with hormone stimulation.Ca²⁺ is a cation carrying positive electric charge.The release of Ca²⁺ from endoplasmic reticulum brings negative electric charge on the membrane of endoplasmic reticulum.It causes the imbalance of electric charge.It needs other cations such as K+,H+ to supplement the lack of positive electric charge.Trimeric intracellular cation channels?TRICs?are a family of counter cation channels located on the membrane of endoplasmic reticulum.In intracellular environment,TRIC-B shows the function of K+ channel.Results and conclusionsWe chose H.armigera and HaEpi cell line as the research materials,used biotechnology methods to investigate the function of TRIC-B during developing stage.Results:The expression of TRIC-B was up-regulated in molting period;Knockdown of TRIC-B led larvae dead for development failure;TRIC-B participates in the 20E induced calcium ion release and influx;TRIC-B was located in cytoplasm;Knockdown of TRIC-B led the HaEpi cells died.Conclusions:TRIC-B supported 20E induced Ca²⁺ release and influx via play a role of counter cation channel;TRIC-B was important in the development of H.armigera.Death of larvae and HaEpi cells which TRIC-B knocked down had been observed.