Structure-Function Relationship Of The Developing Acetylcholine Receptor In Amphibians

Abstract

The nicotinic acetylcholine receptor is responsible for the transfer of signals from the peripheral nervous system to skeletal muscle, resulting in movement. Despite the importance of the acetylcholine receptor, many questions remain unanswered about the relationship between the structure and function of the receptor. The purpose of our research was to explain certain features of the relationship between the amino acid sequence and the function of the amphibian nicotinic acetylcholine receptor. We focused on describing the structural elements underlying the physiologic changes that occur during development and re-innervation of damaged mature muscle. We used molecular biological techniques to alter the amino acid sequence of the receptor and then studied the effects of these alterations using the electrophysiological technique of single channel recording. Our research resulted in the discovery of critical residues involved in two important characteristics of receptor function, the conductance and open time of the ion channel. These results offer new molecular insights into the classic observation that synaptic currents become briefer in duration during the course of muscle development in vertebrates.