Beyer Eric C, Lipkind Gregory M, Kyle John W, Berthoud Viviana M
Department of Pediatrics, University of Chicago, Chicago, IL 60637, USA.
Biochim Biophys Acta. 2012 Aug;1818(8):1823-30. doi: 10.1016/j.bbamem.2011.10.011. Epub 2011 Oct 20.
The amino terminal domain (NT) of the connexins consists of their first 22-23 amino acids. Site-directed mutagenesis studies have demonstrated that NT amino acids are determinants of gap junction channel properties including unitary conductance, permeability/selectivity, and gating in response to transjunctional voltage. The importance of this region has also been emphasized by the identification of multiple disease-associated connexin mutants affecting amino acid residues in the NT region. The first part of the NT is α-helical. The structure of the Cx26 gap junction channel shows that the NT α-helix localizes within the channel, and lines the wall of the pore. Interactions of the amino acid residues in the NT with those in the transmembrane helices may be critical for holding the channel open. The predicted sites of these interactions and the applicability of the Cx26 structure to the NT of other connexins are considered. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
连接蛋白的氨基末端结构域（NT）由其最初的22 - 23个氨基酸组成。定点诱变研究表明，NT氨基酸是间隙连接通道特性的决定因素，包括单位电导、通透性/选择性以及对跨连接电压的门控。通过鉴定影响NT区域氨基酸残基的多个与疾病相关的连接蛋白突变体，也强调了该区域的重要性。NT的第一部分是α螺旋。Cx26间隙连接通道的结构表明，NTα螺旋定位于通道内，并排列在孔壁上。NT中的氨基酸残基与跨膜螺旋中的氨基酸残基之间的相互作用可能对保持通道开放至关重要。考虑了这些相互作用的预测位点以及Cx26结构对其他连接蛋白NT的适用性。本文是名为：通讯连接、组成、结构和特征的特刊的一部分。
