Mutation R184Q of connexin 26 in hearing loss patients has a dominant-negative effect on connexin 26 and connexin 30

Su, Chin-Chuan; Li, Shuan‐Yow; Su, Mu-Chun; Chen, Wei-Chi; Yang, Jiann‐Jou

doi:10.1038/ejhg.2010.50

Cited by 24 publications

(18 citation statements)

References 33 publications

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“…It should be noted that Marziono et al (Marziano et al, 2003) made the W44S, G59A, G59A-EGFP, R75W-GFP mutations in a rat cDNA (and co-expressed these with WT rat Cx26), and that the rat G59A did not form gap junction plaques when expressed alone, whereas we and others (Thomas et al, 2007; Thomas et al, 2004) found that the human G59A mutant did form gap junction plaques when expressed alone. Similarly, our result was also different from a recent report of trafficking defect of the R184Q mutant (Su et al). Technical reasons could account for the discrepancy as Su et al used a complicated Tet-on system in the experiment.…”

Section: Discussioncontrasting

confidence: 99%

Dominant Cx26 mutants associated with hearing loss have dominant-negative effects on wild type Cx26

Zhang¹,

Scherer

Yum

2011

Molecular and Cellular Neuroscience

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Mutations in GJB2, the gene encoding the human gap junction protein connexin26 (Cx26), cause either non-syndromic hearing loss or syndromes affecting both hearing and skin. We have investigated whether dominant Cx26 mutants can interact physically with wild type Cx26. HeLa cells stably expressing wild type Cx26 were transiently transfected to co-express nine individual dominant Cx26 mutants; six associated with non-syndromic hearing loss (W44C, W44S, R143Q, D179N, R184Q, and C202F) and three associated with hearing loss and palmoplantar keratoderma (G59A, R75Q, and R75W). All mutants co-localized and co-immunoprecipitated with wild type Cx26, indicating that they interact physically, likely by forming admixed heteromeric/heterotypic channels. Furthermore, all nine mutants inhibited the transfer of calcein in cells stably expressing Cx26, demonstrating that they each have dominant effects on wild type Cx26. Taken together, these results show that dominant-negative effects of these Cx26 mutants likely contribute to the pathogenesis of hearing loss.

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Section: Discussioncontrasting

confidence: 99%

Dominant Cx26 mutants associated with hearing loss have dominant-negative effects on wild type Cx26

Zhang¹,

Scherer

Yum

2011

Molecular and Cellular Neuroscience

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“…2a). The result differs from that obtained in Cx26WT-GFP expressed HeLa cells [20], which yields the typical punctuate pattern of a gap junction channel between neighboring expressed HeLa cells (Fig. 2b).…”

Section: Resultscontrasting

confidence: 85%

Human Connexin30.2/31.3 (GJC3) does not Form Functional Gap Junction Channels but Causes Enhanced ATP Release in HeLa Cells

Liang

Su²,

Nian

et al. 2011

Cell Biochem Biophys

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Gap junctional intercellular communication has numerous functions, each of which meets the particular needs of organs, tissues, or groups of cells. Connexins (CXs) are homologous four-transmembrane-domain proteins that are the major components of gap junctions. CX30.2/CX31.3 (GJC3) is a relatively new member of the CX protein family. Until now, however, the functional characteristics of CX30.2/CX31.3 have been unclear. To elucidate the properties of CX30.2/CX31.3 channels, their subcellular localization in HeLa cells, their effectiveness in dye transfer, and function on channels were investigated. In the immunofluorescent assay, cells that express CX30.2/CX31.3-GFP exhibited continuous fluorescence along the apposed cell membranes, rather than punctated fluorescence in contacting membranes between two cells. Surprisingly, dyes that can be capable of being permeated by CX26 GJ, according to a scrape loading dye transfer assay in previous studies, are impermeated by CX30.2/CX31.3 GJ, suggesting a difference between the characteristics of CX30.2/CX31.3 GJ and CX26 GJ. Furthermore, a significant amount of ATP was released from the HeLa cells that stably expressed CX30.2/CX31.3, in a medium with low calcium ion concentration, suggesting a hemichannel-based function for CX30.2/CX31.3. Based on these findings, we suggest that CX30.2/CX31.3 shares functional properties with pannexin (hemi) channels rather than gap junction channels of other CXs.

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“…Such a mechanism of action has been proposed for a number of connexin‐based diseases. For example, several Cx26 point mutations, including one involving a proline in the second transmembrane domain, have been described to increase connexon instability (Ambrosi et al, ) and other mutations in Cx26 have been shown to possess dominant negative effects upon not only wild‐type Cx26 but also Cx30 (Su et al, ), with which it can normally form heteromeric hexamers. An intriguing possibility is that the expressed INX1‐PL and INX2‐PL cause the formation of aggregates with those endogenous innexins with which they normally interact in the formation of hexamers, by a prion‐like mechanism such as has been recently proposed for the spread of tau pathologies.…”

Section: Discussionmentioning

confidence: 99%

Expression of a dominant negative mutant innexin in identified neurons and glial cells reveals selective interactions among gap junctional proteins

Yazdani

Firme

Macagno

et al. 2013

Developmental Neurobiology

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Neurons and glia of the medicinal leech CNS express different subsets of the 21 innexin genes encoded in its genome. We report here that the punctal distributions of fluorescently tagged innexin transgenes varies in a stereotypical pattern depending on the innexin expressed. Furthermore, whereas certain innexins colocalize extensively (INX1 and INX14), others do not (e.g., INX1 and INX2 or INX6). We then demonstrate that the mutation of a highly conserved proline residue in the second transmembrane domain of innexins creates a gap junction protein with dominant negative properties. Coexpressing the mutated INX1 gene with its wild type blocks the formation of fluorescent puncta and decouples the expressing neuron from its normal gap junction-coupled network of cells. Similarly, expression of an INX2 mutant transgene (a glial cell innexin), blocks endogenous INX2 puncta and wild-type transgene puncta, and decouples the glial cell from the other glial cells in the ganglion. We show in cell culture with dye-uptake and plasma membrane labeling experiments that the mutant innexin transgene is not expressed on the cell membrane but instead appears to accumulate in the cell's perinuclear region. Lastly, we use these mutant innexin transgenes to show that the INX1 mutant transgene blocks not only INX1 puncta formation, but also puncta of INX14, with which INX1 usually colocalizes. By contrast, the formation of INX6 puncta was unaffected by the INX1 mutant. Together, these experiments suggest that leech innexins can selectively interact with one another to form gap junction plaques, which are heterogeneously located in cellular arbors. © 2013 Wiley Periodicals, Inc. Develop Neurobiol 73: 571-586, 2013.

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Mutation R184Q of connexin 26 in hearing loss patients has a dominant-negative effect on connexin 26 and connexin 30

Cited by 24 publications

References 33 publications

Dominant Cx26 mutants associated with hearing loss have dominant-negative effects on wild type Cx26

Dominant Cx26 mutants associated with hearing loss have dominant-negative effects on wild type Cx26

Human Connexin30.2/31.3 (GJC3) does not Form Functional Gap Junction Channels but Causes Enhanced ATP Release in HeLa Cells

Expression of a dominant negative mutant innexin in identified neurons and glial cells reveals selective interactions among gap junctional proteins

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