Distinct properties and activation of hexameric and heptameric Pannexin 1 channel concatemers.

IF 3.3 2区 医学 Q1 PHYSIOLOGY
Journal of General Physiology Pub Date : 2025-01-06 Epub Date: 2024-12-20 DOI:10.1085/jgp.202413676
Smriti Gupta, Yu-Hsin Chiu, Mohan C Manjegowda, Bimal N Desai, Kodi S Ravichandran, Douglas A Bayliss
{"title":"Distinct properties and activation of hexameric and heptameric Pannexin 1 channel concatemers.","authors":"Smriti Gupta, Yu-Hsin Chiu, Mohan C Manjegowda, Bimal N Desai, Kodi S Ravichandran, Douglas A Bayliss","doi":"10.1085/jgp.202413676","DOIUrl":null,"url":null,"abstract":"<p><p>Pannexin 1 (PANX1) is a member of a topologically related and stoichiometrically diverse family of large pore membrane ion channels that support the flux of signaling metabolites (e.g., ATP) and fluorescent dyes. High-resolution structural analyses have identified PANX1 as a heptamer despite early evidence suggesting that it might be a hexamer. To determine if PANX1 channel activity is supported in both hexameric and heptameric conformations, we examined properties of concatenated PANX1 constructs comprising either six or seven subunits with intact or truncated C-termini (the latter to mimic caspase-cleavage activation). In whole-cell recordings from PANX1-deleted cells, the C-tail-truncated hexameric and heptameric concatemers generated outwardly rectifying PANX1-like currents only after severing the intersubunit linkers. Surprisingly, α1D adrenoceptor stimulation activated constructs with intact or truncated C-tails, even without linker cleavage. In inside-out patches from PANX1-deleted cells, linker cleavage activated C-tail truncated channels derived from either hexameric or heptameric concatemers. The heptamers presented peak unitary conductance and mean open time that was similar to channels assembled from the expression of unlinked single PANX1 subunits and greater than from the hexamers. In addition, the linker-cleaved heptameric concatemers supported greater PANX1-dependent ATP release and TO-PRO-3 uptake than the corresponding hexamers. These data indicate that functional PANX1 channels can be obtained in either hexameric or heptameric conformations and suggest that the distinct unitary properties of heptameric channels are more conducive to large molecule permeation by PANX1; they also suggest that there are distinct structural requirements for C-tail cleavage and receptor-mediated PANX1 activation mechanisms.</p>","PeriodicalId":54828,"journal":{"name":"Journal of General Physiology","volume":"157 1","pages":""},"PeriodicalIF":3.3000,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11666100/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of General Physiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1085/jgp.202413676","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/12/20 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"PHYSIOLOGY","Score":null,"Total":0}
引用次数: 0

Abstract

Pannexin 1 (PANX1) is a member of a topologically related and stoichiometrically diverse family of large pore membrane ion channels that support the flux of signaling metabolites (e.g., ATP) and fluorescent dyes. High-resolution structural analyses have identified PANX1 as a heptamer despite early evidence suggesting that it might be a hexamer. To determine if PANX1 channel activity is supported in both hexameric and heptameric conformations, we examined properties of concatenated PANX1 constructs comprising either six or seven subunits with intact or truncated C-termini (the latter to mimic caspase-cleavage activation). In whole-cell recordings from PANX1-deleted cells, the C-tail-truncated hexameric and heptameric concatemers generated outwardly rectifying PANX1-like currents only after severing the intersubunit linkers. Surprisingly, α1D adrenoceptor stimulation activated constructs with intact or truncated C-tails, even without linker cleavage. In inside-out patches from PANX1-deleted cells, linker cleavage activated C-tail truncated channels derived from either hexameric or heptameric concatemers. The heptamers presented peak unitary conductance and mean open time that was similar to channels assembled from the expression of unlinked single PANX1 subunits and greater than from the hexamers. In addition, the linker-cleaved heptameric concatemers supported greater PANX1-dependent ATP release and TO-PRO-3 uptake than the corresponding hexamers. These data indicate that functional PANX1 channels can be obtained in either hexameric or heptameric conformations and suggest that the distinct unitary properties of heptameric channels are more conducive to large molecule permeation by PANX1; they also suggest that there are distinct structural requirements for C-tail cleavage and receptor-mediated PANX1 activation mechanisms.

六聚体和七聚体Pannexin 1通道连接物的不同性质和活化。
Pannexin 1 (PANX1)是一个具有拓扑关系和化学计量多样性的大孔膜离子通道家族的成员,支持信号代谢产物(如ATP)和荧光染料的通量。尽管早期证据表明PANX1可能是六聚体,但高分辨率结构分析已确定PANX1为七聚体。为了确定PANX1通道活性是否在六聚体和七聚体构象中都得到支持,我们检查了由6个或7个亚基组成的连接PANX1构象的性质,这些亚基具有完整的或截断的c -末端(后者模拟caspase切割激活)。在panx1缺失细胞的全细胞记录中,c尾截断的六聚体和七聚体仅在切断亚基间连接体后才产生向外整流的panx1样电流。令人惊讶的是,α1D肾上腺素能受体刺激激活了完整或截断的c -尾构建体,即使没有连接体切割。在panx1缺失细胞的内向外补片中,连接体切割激活了六聚体或七聚体串联体衍生的c尾截断通道。七聚体的峰值电导和平均打开时间与未连接的PANX1亚基表达组装的通道相似,且大于六聚体。此外,连接切割的七聚体比相应的六聚体支持更多的panx1依赖性ATP释放和TO-PRO-3摄取。这些数据表明,在六聚体和七聚体构象中都可以获得功能性的PANX1通道,七聚体通道具有明显的单一性,更有利于PANX1大分子渗透;它们还表明,c尾切割和受体介导的PANX1激活机制存在不同的结构要求。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
CiteScore
6.00
自引率
10.50%
发文量
88
审稿时长
6-12 weeks
期刊介绍: General physiology is the study of biological mechanisms through analytical investigations, which decipher the molecular and cellular mechanisms underlying biological function at all levels of organization. The mission of Journal of General Physiology (JGP) is to publish mechanistic and quantitative molecular and cellular physiology of the highest quality, to provide a best-in-class author experience, and to nurture future generations of independent researchers. The major emphasis is on physiological problems at the cellular and molecular level.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信