Enzyme Domain Affects the Movement of the Voltage Sensor in Ascidian and Zebrafish Voltage-sensing Phosphatases

摘要: The ascidian voltage-sensing phosphatase (Ci-VSP) consists of the voltage sensor domain (VSD) and a cytoplasmic region that has significant homology to tensin homolog deleted on chromosome TEN (PTEN). activity Ci-VSP is modified by conformational change VSD. In many proteins, two protein modules are bidirectionally coupled, but it unknown whether could affect movement VSD in VSP. We addressed this issue whole-cell patch recording gating currents from teleost VSP (Dr-VSP) cloned Danio rerio expressed tsA201 cells. Replacement critical cysteine residue, active center Dr-VSP, serine sharpened both ON- OFF-gating currents. Similar changes were produced treatment with inhibitors, pervanadate orthovanadate, constitutively bind catalytic phosphatases. distinct kinetics dependent enzyme not because altered phosphatidylinositol 4,5-bisphosphate levels, current did depletion 4,5-bisphosphate, as reported coexpressed KCNQ2/3 channels. These results indicate influenced enzymatic state domain, providing an important clue for understanding mechanisms coupling between its effector.