The Nicotinic Acetylcholine Receptors and Its Subunits: From Structure to Function

Abstract: The nicotinic acetylcholine receptors are legend-gated ion channels. Each receptor is composed of 5 subunits， and each subunit has 4 α-helix transmembrane domains. The channel pore is shaped by an inner ring of 5 α-helices of M2， which curve radially to create a tapering path in the middle of membrane， and an outer ring of 15 α-helices which coil around each other and shield the inner ring from the lipid. So far 17 subunits of the receptors have been determined， which belong to a big gene family with a same origin and are expressed in the central nervous system， peripheral nervous system and muscle tissue. There are so many subunits and specific expression in different tissues， which result in their many physiological and pharmacological features and functions. Recently genetically manipulated mice， such as gene knock-out mice， have greatly increased our understanding of the subunit composition and physiological properties of the receptors in vivo. In this article， we review the related researching progress.

CSTR: 32200.14.cjcb.2004.03.0003