ACCTG 1 Lecture Notes - Lecture 38: Dorsal Root Ganglion, Nav1.7, Channelopathy
Document Summary
Structure and function of voltage gated ion channels. Sodium channel structure and function: voltage sensitivity (mechanism of activation, 4th transmembrane helix (s4) of each domain has a few basic amino acids in the same place. Refractory period: ensures unidirectional, can"t be generated immediately after another, as channels close again, 9 genes form na+ channels. Case study: neuronal sodium channelopathy can"t experience pain, mutation in scn9a can"t make nav1. 7 protein for its channel. In mutant shaker drosophila, legs shake with anaesthesia: electrophysiology showed ka channels were affected, sequenced gene 616 amino acids, about 70kda, 6 transmembrane helices, resembled one of our four domains of vg sodium channels, clearly related. Led to discovery of related genes in drosophila: 4 vg potassium in drosophila with different inactivations. Intermediates of k and ka: orthologs of these channels are in humans, some duplicated result of invertebrate duplications early on.
