Isoform-specific phosphorylation-dependent regulation of connexin hemichannels

Research output: Contribution to journalJournal article

Standard

Isoform-specific phosphorylation-dependent regulation of connexin hemichannels. / Alstrøm, Jette Skov; Hansen, Daniel Bloch; Nielsen, Morten Schak; MacAulay, Nanna.

In: Journal of Neurophysiology, Vol. 114, No. 5, 15.11.2015, p. 3014-22.

Research output: Contribution to journalJournal article

Harvard

Alstrøm, JS, Hansen, DB, Nielsen, MS & MacAulay, N 2015, 'Isoform-specific phosphorylation-dependent regulation of connexin hemichannels', Journal of Neurophysiology, vol. 114, no. 5, pp. 3014-22. https://doi.org/10.1152/jn.00575.2015

APA

Alstrøm, J. S., Hansen, D. B., Nielsen, M. S., & MacAulay, N. (2015). Isoform-specific phosphorylation-dependent regulation of connexin hemichannels. Journal of Neurophysiology, 114(5), 3014-22. https://doi.org/10.1152/jn.00575.2015

Vancouver

Alstrøm JS, Hansen DB, Nielsen MS, MacAulay N. Isoform-specific phosphorylation-dependent regulation of connexin hemichannels. Journal of Neurophysiology. 2015 Nov 15;114(5):3014-22. https://doi.org/10.1152/jn.00575.2015

Author

Alstrøm, Jette Skov ; Hansen, Daniel Bloch ; Nielsen, Morten Schak ; MacAulay, Nanna. / Isoform-specific phosphorylation-dependent regulation of connexin hemichannels. In: Journal of Neurophysiology. 2015 ; Vol. 114, No. 5. pp. 3014-22.

Bibtex

@article{99f172cf22db4f3393cd4ba38d1602e4,
title = "Isoform-specific phosphorylation-dependent regulation of connexin hemichannels",
abstract = "Connexins form gap junction channels made up of two connexons (hemichannels) from adjacent cells. Unopposed hemichannels may open toward the extracellular space upon stimulation by, e.g., removal of divalent cations from the extracellular solution and allow isoform-specific transmembrane flux of fluorescent dyes and physiologically relevant molecules, such as ATP and ions. Connexin (Cx)43 and Cx30 are the major astrocytic connexins. Protein kinase C (PKC) regulates Cx43 in its cell-cell gap junction configuration and may also act to keep Cx43 hemichannels closed. In contrast, the regulation of Cx30 hemichannels by PKC is unexplored. To determine phosphorylation-dependent regulation of Cx30 and Cx43 hemichannels, these were heterologously expressed in Xenopus laevis oocytes and opened with divalent cation-free solution. Inhibition of PKC activity did not affect hemichannel opening of either connexin. PKC activation had no effect on Cx43-mediated hemichannel activity, whereas both dye uptake and current through Cx30 hemichannels were reduced. We detected no PKC-induced connexin internalization from the plasma membrane, indicating that PKC reduced Cx30 hemichannel activity by channel closure. In an attempt to resolve the PKC phosphorylation site(s) on Cx30, alanine mutations of putative cytoplasmic PKC consensus sites were created to prevent phosphorylation (T5A, T8A, T102A, S222A, S225A, S239A, and S258A). These Cx30 mutants responded to PKC activation, suggesting that Cx30 hemichannels are not regulated by phosphorylation of a single site. In conclusion, Cx30, but not Cx43, hemichannels close upon PKC activation, illustrating that connexin hemichannels display not only isoform-specific permeability profiles but also isoform-specific regulation by PKC.",
author = "Alstr{\o}m, {Jette Skov} and Hansen, {Daniel Bloch} and Nielsen, {Morten Schak} and Nanna MacAulay",
note = "Copyright {\circledC} 2015 the American Physiological Society.",
year = "2015",
month = "11",
day = "15",
doi = "10.1152/jn.00575.2015",
language = "English",
volume = "114",
pages = "3014--22",
journal = "Journal of Neurophysiology",
issn = "0022-3077",
publisher = "American Physiological Society",
number = "5",

}

RIS

TY - JOUR

T1 - Isoform-specific phosphorylation-dependent regulation of connexin hemichannels

AU - Alstrøm, Jette Skov

AU - Hansen, Daniel Bloch

AU - Nielsen, Morten Schak

AU - MacAulay, Nanna

N1 - Copyright © 2015 the American Physiological Society.

PY - 2015/11/15

Y1 - 2015/11/15

N2 - Connexins form gap junction channels made up of two connexons (hemichannels) from adjacent cells. Unopposed hemichannels may open toward the extracellular space upon stimulation by, e.g., removal of divalent cations from the extracellular solution and allow isoform-specific transmembrane flux of fluorescent dyes and physiologically relevant molecules, such as ATP and ions. Connexin (Cx)43 and Cx30 are the major astrocytic connexins. Protein kinase C (PKC) regulates Cx43 in its cell-cell gap junction configuration and may also act to keep Cx43 hemichannels closed. In contrast, the regulation of Cx30 hemichannels by PKC is unexplored. To determine phosphorylation-dependent regulation of Cx30 and Cx43 hemichannels, these were heterologously expressed in Xenopus laevis oocytes and opened with divalent cation-free solution. Inhibition of PKC activity did not affect hemichannel opening of either connexin. PKC activation had no effect on Cx43-mediated hemichannel activity, whereas both dye uptake and current through Cx30 hemichannels were reduced. We detected no PKC-induced connexin internalization from the plasma membrane, indicating that PKC reduced Cx30 hemichannel activity by channel closure. In an attempt to resolve the PKC phosphorylation site(s) on Cx30, alanine mutations of putative cytoplasmic PKC consensus sites were created to prevent phosphorylation (T5A, T8A, T102A, S222A, S225A, S239A, and S258A). These Cx30 mutants responded to PKC activation, suggesting that Cx30 hemichannels are not regulated by phosphorylation of a single site. In conclusion, Cx30, but not Cx43, hemichannels close upon PKC activation, illustrating that connexin hemichannels display not only isoform-specific permeability profiles but also isoform-specific regulation by PKC.

AB - Connexins form gap junction channels made up of two connexons (hemichannels) from adjacent cells. Unopposed hemichannels may open toward the extracellular space upon stimulation by, e.g., removal of divalent cations from the extracellular solution and allow isoform-specific transmembrane flux of fluorescent dyes and physiologically relevant molecules, such as ATP and ions. Connexin (Cx)43 and Cx30 are the major astrocytic connexins. Protein kinase C (PKC) regulates Cx43 in its cell-cell gap junction configuration and may also act to keep Cx43 hemichannels closed. In contrast, the regulation of Cx30 hemichannels by PKC is unexplored. To determine phosphorylation-dependent regulation of Cx30 and Cx43 hemichannels, these were heterologously expressed in Xenopus laevis oocytes and opened with divalent cation-free solution. Inhibition of PKC activity did not affect hemichannel opening of either connexin. PKC activation had no effect on Cx43-mediated hemichannel activity, whereas both dye uptake and current through Cx30 hemichannels were reduced. We detected no PKC-induced connexin internalization from the plasma membrane, indicating that PKC reduced Cx30 hemichannel activity by channel closure. In an attempt to resolve the PKC phosphorylation site(s) on Cx30, alanine mutations of putative cytoplasmic PKC consensus sites were created to prevent phosphorylation (T5A, T8A, T102A, S222A, S225A, S239A, and S258A). These Cx30 mutants responded to PKC activation, suggesting that Cx30 hemichannels are not regulated by phosphorylation of a single site. In conclusion, Cx30, but not Cx43, hemichannels close upon PKC activation, illustrating that connexin hemichannels display not only isoform-specific permeability profiles but also isoform-specific regulation by PKC.

U2 - 10.1152/jn.00575.2015

DO - 10.1152/jn.00575.2015

M3 - Journal article

C2 - 26400258

VL - 114

SP - 3014

EP - 3022

JO - Journal of Neurophysiology

JF - Journal of Neurophysiology

SN - 0022-3077

IS - 5

ER -

ID: 153755606