Narahari AK, Kreutzberger AJB, Gaete PS, Chiu YH, Leonhardt SA, Medina CB, Jin X, Oleniacz PW, Kiessling V, Barrett PQ, Ravichandran KS, Yeager M, Contreras JE, Tamm LK, Bayliss DA. ATP and large signaling metabolites flux through caspase-activated Pannexin 1 channels.
eLife 2021;
10:e64787. [PMID:
33410749 PMCID:
PMC7806264 DOI:
10.7554/elife.64787]
[Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 01/05/2021] [Indexed: 12/16/2022] Open
Abstract
Pannexin 1 (Panx1) is a membrane channel implicated in numerous physiological and pathophysiological processes via its ability to support release of ATP and other cellular metabolites for local intercellular signaling. However, to date, there has been no direct demonstration of large molecule permeation via the Panx1 channel itself, and thus the permselectivity of Panx1 for different molecules remains unknown. To address this, we expressed, purified, and reconstituted Panx1 into proteoliposomes and demonstrated that channel activation by caspase cleavage yields a dye-permeable pore that favors flux of anionic, large-molecule permeants (up to ~1 kDa). Large cationic molecules can also permeate the channel, albeit at a much lower rate. We further show that Panx1 channels provide a molecular pathway for flux of ATP and other anionic (glutamate) and cationic signaling metabolites (spermidine). These results verify large molecule permeation directly through caspase-activated Panx1 channels that can support their many physiological roles.
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