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Cell Mol Neurobiol
2004 Oct 01;245:647-65. doi: 10.1023/b:cemn.0000036403.43484.3d.
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Properties of connexin26 hemichannels expressed in Xenopus oocytes.
Ripps H
,
Qian H
,
Zakevicius J
.
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1. Hemichannels formed by connexin26 (Cx26) on the horizontal cell dendrites that invaginate cone terminals in the vertebrate retina have been implicated in the feedback mechanism by which horizontal cells regulate transmitter release from cone photoreceptors. However, their membrane properties had not been studied previously, and it was unclear whether they could subserve their purported function at the membrane potentials over which horizontal cells operate. 2. We used the two-electrode voltage clamp technique to record the membrane currents and pharmacological properties of Cx26 hemichannels formed in the Xenopus oocyte expression system. 3. Oocytes expressing Cx26 exhibited large membrane conductances over a broad range of hyperpolarizing and depolarizing membrane potentials, and displayed little evidence of voltage-dependent gating, indicating that the hemichannels are constitutively open. The Cx26-mediated nonjunctional currents were relatively insensitive to quinine, a cinchona alkaloid that opens hemichannels formed by several other connexins. However, the hemichannel currents were blocked by carbenoxolone, a rise in extracellular calcium, or lowering intracellular pH. The currents could also be suppressed by reducing extracellular pH, and by the chloride channel blocker NPPB through its direct interaction with Cx26 hemichannels. 4. These findings provide a basis with which to evaluate the in situ pharmacological studies that attempt to assess the putative role of Cx26 hemichannels in the feedback pathway in the distalretina.
Ahmad,
Post-translational integration and oligomerization of connexin 26 in plasma membranes and evidence of formation of membrane pores: implications for the assembly of gap junctions.
2002, Pubmed
Ahmad,
Post-translational integration and oligomerization of connexin 26 in plasma membranes and evidence of formation of membrane pores: implications for the assembly of gap junctions.
2002,
Pubmed
Al-Ubaidi,
Functional properties, developmental regulation, and chromosomal localization of murine connexin36, a gap-junctional protein expressed preferentially in retina and brain.
2000,
Pubmed
,
Xenbase
Arnos,
Genetics of hearing disorders.
1992,
Pubmed
Barnes,
Modulation of transmission gain by protons at the photoreceptor output synapse.
1993,
Pubmed
Baud,
Sodium channels induced by depolarization of the Xenopus laevis oocyte.
1982,
Pubmed
,
Xenbase
Beahm,
Hemichannel and junctional properties of connexin 50.
2002,
Pubmed
,
Xenbase
Cohen-Salmon,
Targeted ablation of connexin26 in the inner ear epithelial gap junction network causes hearing impairment and cell death.
2002,
Pubmed
Dascal,
The use of Xenopus oocytes for the study of ion channels.
1987,
Pubmed
,
Xenbase
Davidson,
Reversible inhibition of intercellular junctional communication by glycyrrhetinic acid.
1986,
Pubmed
DeVries,
Exocytosed protons feedback to suppress the Ca2+ current in mammalian cone photoreceptors.
2001,
Pubmed
DeVries,
Hemi-gap-junction channels in solitary horizontal cells of the catfish retina.
1992,
Pubmed
Dixon,
Quinine, intracellular pH and modulation of hemi-gap junctions in catfish horizontal cells.
1996,
Pubmed
Dmitriev,
Circadian clock regulation of pH in the rabbit retina.
2001,
Pubmed
Ebihara,
Cloning and expression of a Xenopus embryonic gap junction protein.
1989,
Pubmed
,
Xenbase
Eckert,
A distinct membrane current in rat lens fiber cells isolated under calcium-free conditions.
1998,
Pubmed
,
Xenbase
Eskandari,
Inhibition of gap junction hemichannels by chloride channel blockers.
2002,
Pubmed
,
Xenbase
Falk,
Biosynthesis and structural composition of gap junction intercellular membrane channels.
2000,
Pubmed
Frenz,
Immunolocalization of connexin 26 in the developing mouse cochlea.
2000,
Pubmed
George,
Intracellular trafficking pathways in the assembly of connexins into gap junctions.
1999,
Pubmed
Hirasawa,
pH changes in the invaginating synaptic cleft mediate feedback from horizontal cells to cone photoreceptors by modulating Ca2+ channels.
2003,
Pubmed
Janssen-Bienhold,
Identification and localization of connexin26 within the photoreceptor-horizontal cell synaptic complex.
2001,
Pubmed
John,
Connexin-43 hemichannels opened by metabolic inhibition.
1999,
Pubmed
Kamermans,
Hemichannel-mediated inhibition in the outer retina.
2001,
Pubmed
Kamermans,
The feedback pathway from horizontal cells to cones. A mini review with a look ahead.
1999,
Pubmed
Kelley,
Novel mutations in the connexin 26 gene (GJB2) that cause autosomal recessive (DFNB1) hearing loss.
1998,
Pubmed
Kelsell,
Connexin 26 mutations in hereditary non-syndromic sensorineural deafness.
1997,
Pubmed
Kikuchi,
Gap junctions in the rat cochlea: immunohistochemical and ultrastructural analysis.
1995,
Pubmed
Kondo,
Metabolic inhibition activates a non-selective current through connexin hemichannels in isolated ventricular myocytes.
2000,
Pubmed
Krafte,
Hydrogen ion modulation of Ca channel current in cardiac ventricular cells. Evidence for multiple mechanisms.
1988,
Pubmed
Lautermann,
Developmental expression patterns of connexin26 and -30 in the rat cochlea.
1999,
Pubmed
Li,
Properties and regulation of gap junctional hemichannels in the plasma membranes of cultured cells.
1996,
Pubmed
Locke,
Developmental expression and assembly of connexins into homomeric and heteromeric gap junction hemichannels in the mouse mammary gland.
2000,
Pubmed
Malchow,
A novel action of quinine and quinidine on the membrane conductance of neurons from the vertebrate retina.
1994,
Pubmed
Malchow,
Evidence for hemi-gap junctional channels in isolated horizontal cells of the skate retina.
1993,
Pubmed
Martin,
Multiple pathways in the trafficking and assembly of connexin 26, 32 and 43 into gap junction intercellular communication channels.
2001,
Pubmed
Miledi,
Membrane currents elicited by divalent cations in Xenopus oocytes.
1989,
Pubmed
,
Xenbase
Musil,
Biochemical analysis of connexin43 intracellular transport, phosphorylation, and assembly into gap junctional plaques.
1991,
Pubmed
Musil,
Multisubunit assembly of an integral plasma membrane channel protein, gap junction connexin43, occurs after exit from the ER.
1993,
Pubmed
,
Xenbase
Oh,
Stoichiometry of transjunctional voltage-gating polarity reversal by a negative charge substitution in the amino terminus of a connexin32 chimera.
2000,
Pubmed
,
Xenbase
Parkerson,
Contribution of chloride channels to volume regulation of cortical astrocytes.
2003,
Pubmed
Paul,
Connexin46, a novel lens gap junction protein, induces voltage-gated currents in nonjunctional plasma membrane of Xenopus oocytes.
1991,
Pubmed
,
Xenbase
Pfahnl,
Gating of cx46 gap junction hemichannels by calcium and voltage.
1999,
Pubmed
,
Xenbase
Pottek,
Contribution of connexin26 to electrical feedback inhibition in the turtle retina.
2003,
Pubmed
Qian,
Gap-junctional properties of electrically coupled skate horizontal cells in culture.
1993,
Pubmed
Quist,
Physiological role of gap-junctional hemichannels. Extracellular calcium-dependent isosmotic volume regulation.
2000,
Pubmed
Rae,
The large-conductance potassium ion channel of rabbit corneal epithelium is blocked by quinidine.
1992,
Pubmed
Ripps,
Pharmacological enhancement of hemi-gap-junctional currents in Xenopus oocytes.
2002,
Pubmed
,
Xenbase
Ripps,
Blockade of an inward sodium current facilitates pharmacological study of hemi-gap-junctional currents in Xenopus oocytes.
2002,
Pubmed
,
Xenbase
Spicer,
Evidence for a medial K+ recycling pathway from inner hair cells.
1998,
Pubmed
Srinivas,
Quinine blocks specific gap junction channel subtypes.
2001,
Pubmed
Srinivas,
Closure of gap junction channels by arylaminobenzoates.
2003,
Pubmed
Tekin,
W44C mutation in the connexin 26 gene associated with dominant non-syndromic deafness.
2001,
Pubmed
Thoreson,
Reciprocal interactions between calcium and chloride in rod photoreceptors.
2003,
Pubmed
Tokimasa,
Effects of barium, lanthanum and gadolinium on endogenous chloride and potassium currents in Xenopus oocytes.
1996,
Pubmed
,
Xenbase
Trexler,
Voltage gating and permeation in a gap junction hemichannel.
1996,
Pubmed
,
Xenbase
Trexler,
Rapid and direct effects of pH on connexins revealed by the connexin46 hemichannel preparation.
1999,
Pubmed
,
Xenbase
Verselis,
Connexin hemichannels and cell-cell channels: comparison of properties.
2000,
Pubmed
,
Xenbase
Weber,
Endogenous ion channels in oocytes of xenopus laevis: recent developments.
1999,
Pubmed
,
Xenbase
White,
Genetic diseases and gene knockouts reveal diverse connexin functions.
1999,
Pubmed
White,
Functional characteristics of skate connexin35, a member of the gamma subfamily of connexins expressed in the vertebrate retina.
1999,
Pubmed
,
Xenbase
White,
Functional analysis of human Cx26 mutations associated with deafness.
2000,
Pubmed
,
Xenbase
Wu,
NPPB block of Ca(++)-activated Cl- currents in Xenopus oocytes.
1992,
Pubmed
,
Xenbase
Yamamoto,
Effects of light and darkness on pH outside rod photoreceptors in the cat retina.
1992,
Pubmed
Ye,
Functional hemichannels in astrocytes: a novel mechanism of glutamate release.
2003,
Pubmed
Yeager,
Synthesis, assembly and structure of gap junction intercellular channels.
1998,
Pubmed
Yeh,
Mechanism of action of quinidine on squid axon membranes.
1976,
Pubmed
Zhang,
Membrane integration of in vitro-translated gap junctional proteins: co- and post-translational mechanisms.
1996,
Pubmed
Zhang,
Sequence and tissue distribution of a second protein of hepatic gap junctions, Cx26, as deduced from its cDNA.
1989,
Pubmed
