Permeant-specific gating of connexin 30 hemichannels

Research output: Contribution to journalJournal articlepeer-review

Standard

Permeant-specific gating of connexin 30 hemichannels. / Nielsen, Brian Skriver; Alstrom, Jette Skov; Nicholson, Bruce; Nielsen, Morten Schak; Macaulay, Nanna.

In: Journal of Biological Chemistry, Vol. 292, No. 49, 2017, p. 19999-20009.

Research output: Contribution to journalJournal articlepeer-review

Harvard

Nielsen, BS, Alstrom, JS, Nicholson, B, Nielsen, MS & Macaulay, N 2017, 'Permeant-specific gating of connexin 30 hemichannels', Journal of Biological Chemistry, vol. 292, no. 49, pp. 19999-20009. https://doi.org/10.1074/jbc.M117.805986

APA

Nielsen, B. S., Alstrom, J. S., Nicholson, B., Nielsen, M. S., & Macaulay, N. (2017). Permeant-specific gating of connexin 30 hemichannels. Journal of Biological Chemistry, 292(49), 19999-20009. https://doi.org/10.1074/jbc.M117.805986

Vancouver

Nielsen BS, Alstrom JS, Nicholson B, Nielsen MS, Macaulay N. Permeant-specific gating of connexin 30 hemichannels. Journal of Biological Chemistry. 2017;292(49):19999-20009. https://doi.org/10.1074/jbc.M117.805986

Author

Nielsen, Brian Skriver ; Alstrom, Jette Skov ; Nicholson, Bruce ; Nielsen, Morten Schak ; Macaulay, Nanna. / Permeant-specific gating of connexin 30 hemichannels. In: Journal of Biological Chemistry. 2017 ; Vol. 292, No. 49. pp. 19999-20009.

Bibtex

@article{d87c83cb1a764ac9893185872429b883,
title = "Permeant-specific gating of connexin 30 hemichannels",
abstract = "Gap junctions confer interconnectivity of the cytoplasm in neighboring cells via docking of two connexons expressed in each of the adjacent membranes. Undocked connexons, referred to as hemichannels, may open and connect the cytoplasm with the extracellular fluid. The hemichannel configuration of connexins (Cxs) displays isoform-specific permeability profiles that are not directly determined by the size and charge of the permeant. To further explore Ca2+-mediated gating and permeability features of connexin hemichannels, we heterologously expressed Cx30 hemichannels in Xenopus laevis oocytes. The sensitivity toward divalent cation-mediated gating differed between small atomic ions (current) and fluorescent dye permeants, indicating that these permeants are distinctly gated. Three aspartate residues in Cx30 (D50, D172 and D179) have previously been implicated in the Ca2+ sensitivity of other hemichannel isoforms. While the aspartate at position D50 was indispensable for divalent cation-dependent gating of Cx30 hemichannels, substitutions of the two other residues had no significant effect on gating, illustrating differences in the gating mechanisms between connexin isoforms. Using the substituted-cysteine accessibility method (SCAM), we evaluated the role of possible pore-lining residues in the permeation of ions and ethidium through Cx30 hemichannels. Of the cysteine-substituted residues, interaction of a proposed pore-lining cysteine at position 37 with the positively charged compound [2-(trimethylammonium)ethyl] methane thiosulfonate bromide (MTS-ET) increased Cx30-mediated currents, with unperturbed ethidium permeability. In summary, our results demonstrate that the permeability of hemichannels is regulated in a permeant-specific manner, and underscores that hemichannels are selective rather than non-discriminating and freely-diffusable pores.",
author = "Nielsen, {Brian Skriver} and Alstrom, {Jette Skov} and Bruce Nicholson and Nielsen, {Morten Schak} and Nanna Macaulay",
year = "2017",
doi = "10.1074/jbc.M117.805986",
language = "English",
volume = "292",
pages = "19999--20009",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology, Inc.",
number = "49",

}

RIS

TY - JOUR

T1 - Permeant-specific gating of connexin 30 hemichannels

AU - Nielsen, Brian Skriver

AU - Alstrom, Jette Skov

AU - Nicholson, Bruce

AU - Nielsen, Morten Schak

AU - Macaulay, Nanna

PY - 2017

Y1 - 2017

N2 - Gap junctions confer interconnectivity of the cytoplasm in neighboring cells via docking of two connexons expressed in each of the adjacent membranes. Undocked connexons, referred to as hemichannels, may open and connect the cytoplasm with the extracellular fluid. The hemichannel configuration of connexins (Cxs) displays isoform-specific permeability profiles that are not directly determined by the size and charge of the permeant. To further explore Ca2+-mediated gating and permeability features of connexin hemichannels, we heterologously expressed Cx30 hemichannels in Xenopus laevis oocytes. The sensitivity toward divalent cation-mediated gating differed between small atomic ions (current) and fluorescent dye permeants, indicating that these permeants are distinctly gated. Three aspartate residues in Cx30 (D50, D172 and D179) have previously been implicated in the Ca2+ sensitivity of other hemichannel isoforms. While the aspartate at position D50 was indispensable for divalent cation-dependent gating of Cx30 hemichannels, substitutions of the two other residues had no significant effect on gating, illustrating differences in the gating mechanisms between connexin isoforms. Using the substituted-cysteine accessibility method (SCAM), we evaluated the role of possible pore-lining residues in the permeation of ions and ethidium through Cx30 hemichannels. Of the cysteine-substituted residues, interaction of a proposed pore-lining cysteine at position 37 with the positively charged compound [2-(trimethylammonium)ethyl] methane thiosulfonate bromide (MTS-ET) increased Cx30-mediated currents, with unperturbed ethidium permeability. In summary, our results demonstrate that the permeability of hemichannels is regulated in a permeant-specific manner, and underscores that hemichannels are selective rather than non-discriminating and freely-diffusable pores.

AB - Gap junctions confer interconnectivity of the cytoplasm in neighboring cells via docking of two connexons expressed in each of the adjacent membranes. Undocked connexons, referred to as hemichannels, may open and connect the cytoplasm with the extracellular fluid. The hemichannel configuration of connexins (Cxs) displays isoform-specific permeability profiles that are not directly determined by the size and charge of the permeant. To further explore Ca2+-mediated gating and permeability features of connexin hemichannels, we heterologously expressed Cx30 hemichannels in Xenopus laevis oocytes. The sensitivity toward divalent cation-mediated gating differed between small atomic ions (current) and fluorescent dye permeants, indicating that these permeants are distinctly gated. Three aspartate residues in Cx30 (D50, D172 and D179) have previously been implicated in the Ca2+ sensitivity of other hemichannel isoforms. While the aspartate at position D50 was indispensable for divalent cation-dependent gating of Cx30 hemichannels, substitutions of the two other residues had no significant effect on gating, illustrating differences in the gating mechanisms between connexin isoforms. Using the substituted-cysteine accessibility method (SCAM), we evaluated the role of possible pore-lining residues in the permeation of ions and ethidium through Cx30 hemichannels. Of the cysteine-substituted residues, interaction of a proposed pore-lining cysteine at position 37 with the positively charged compound [2-(trimethylammonium)ethyl] methane thiosulfonate bromide (MTS-ET) increased Cx30-mediated currents, with unperturbed ethidium permeability. In summary, our results demonstrate that the permeability of hemichannels is regulated in a permeant-specific manner, and underscores that hemichannels are selective rather than non-discriminating and freely-diffusable pores.

U2 - 10.1074/jbc.M117.805986

DO - 10.1074/jbc.M117.805986

M3 - Journal article

C2 - 28982982

VL - 292

SP - 19999

EP - 20009

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 49

ER -

ID: 186318390