Developmental Regulation and Structural Organization of Connexins in Epidermal Gap Junctions

Risek, Boris; Fg, Klier; Nb, Gilula

doi:10.1006/dbio.1994.1190

Cited by 79 publications

(45 citation statements)

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“…Moreover, Cx26 was not isolated along with Cx43 when connexons were analyzed by centrifugation through sucrose gradients or by affinity chromatography. The lack of heteromeric mixing by Cx26 and Cx43 is consistent with the previous observations suggesting lack of precise colocalization of co-expressed Cx26 and Cx43 (Spray et al, 1991;Risek et al, 1994;Falk, 2000) and demonstrates their inability to form functional heterotypic channels in paired Xenopus oocytes (White et al, 1995) or to allow dye transfer in transfected cells (Elfgang et al, 1995).…”

Section: Discussionsupporting

confidence: 90%

“…For example, Spray et al (Spray et al, 1991) found that Cx26 and Cx43 localize to discrete positions at appositional membranes in cultured leptomeningeal cells and make identifiable channels of discrete sizes. Risek et al (Risek et al, 1994) identified very large gap junctions in epidermal cells that contained discrete domains of Cx26 or Cx43 immunoreactivity. Heterotypic pairing of Cx26 and Cx43 did not result in electrical coupling in paired Xenopus oocytes (White et al, 1995) nor did it allow dye 2469 Many cells contain two (or more) gap junction proteins that are able to oligomerize with each other to form heteromeric gap junction channels and influence the properties of intercellular communication.…”

Section: Introductionmentioning

confidence: 96%

“…Several lines of evidence suggested that Cx26 and Cx43 might be good candidates. These two connexins are found together in a number of tissues or organs such as mammary epithelium (Tomasetto et al, 1993), skin (Risek et al, 1994;Goliger and Paul, 1995), colchea (Kikuchi et al, 2000) and testes (Brehm et al, 2002). Indeed, in leptomeningeal cells (Spray et al, 1991), thyroid cells (Meda et al, 1993), epidermal cells (Risek et al, 1994), P19 embryonal carcinoma cells (Belliveau et al, 1997), hypothalamic neuronal cell lines (Charles et al, 1996), lung epithelial cells (Lee et al, 1997) and astrocytes (Nagy et al, 2001), Cx26 and Cx43 are present in the same cells.…”

Section: Introductionmentioning

confidence: 99%

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Connexin43 and connexin26 form gap junctions, but not heteromeric channels in co-expressing cells

Gemel

Valiūnas

Brink

et al. 2004

Journal of Cell Science

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solubilized connexons from co-expressing cells by centrifugation through sucrose gradients or by affinity purification using a Ni-NTA column showed no evidence of mixing of Cx26 and Cx43. These results contrast with our observations in cells co-expressing other connexins with Cx43 and suggest that Cx26 and Cx43 do not form heteromeric hemichannels. Moreover, the incorporation of Cx26 and Cx43 into oligomers and into the membrane were similarly affected by treatment of co-expressing cells with brefeldin A or nocodazole, suggesting that the lack of mixing is due to incompatibility of these connexins, not to differences in biosynthetic trafficking.

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Section: Discussionsupporting

confidence: 90%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

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Connexin43 and connexin26 form gap junctions, but not heteromeric channels in co-expressing cells

Gemel

Valiūnas

Brink

et al. 2004

Journal of Cell Science

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“…We have no clear explanation for the differences between our results and theirs. Nevertheless, our findings are more consistent with patterns of connexin expression in the epidermis (Risek et al, 1992;Kamibayashi et al, 1993;Butterweck et al, 1994;Goliger and Paul, 1994;Risek et al, 1994;Salomon, et al, 1994 There were two properties of intercellular communication in wounded epidermis that appeared to be inconsistent with connexin expression patterns. The first was that basal and lowest spinous cells in the proliferative zones and regenerating epithelium transferred dye efficiently but apparently lacked Cx26, Cx31.1, and Cx43.…”

Section: Discussionsupporting

confidence: 87%

Wounding alters epidermal connexin expression and gap junction-mediated intercellular communication.

Goliger

Paul

1995

MBoC

180

181

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We show that connexin expression and in vivo patterns of communication were dramatically altered in response to epidermal wounding. Six hours after injury, Cx26 was up-regulated in the differentiated cells proximal to the wound, but was down-regulated in cells located at the wound edge. In contrast, Cx31.1 and Cx43 were down-regulated in cells both peripheral to and at the wounded edge. These patterns of altered connexin expression were detectable as early as 2 h after wounding and were most pronounced in 24-h old wounds. Increased expression of Cx26 was still evident in the hyperproliferative epidermis of 6-day old wounds. In vivo dye transfer experiments with Lucifer yellow and neurobiotin confirmed that junctional communication patterns were altered in ways consistent with changes in connexin expression. The data thus suggest that intercellular communication is intimately involved in regulating epidermal wound repair.

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“…7I). Some spots showed adjacent red and green, suggesting the presence of both Cx26 and mutant Cx43 (without mixing) in the same gap junction plaques as has been seen with co-expressed wildtype Cx26 and Cx43 (Risek et al, 1994;Falk, 2000;Gemel et al, 2004).…”

Section: Effects Of Sg Substitutions On Heteromeric Compatibilitymentioning

confidence: 58%

N-terminal residues in Cx43 and Cx40 determine physiological properties of gap junction channels, but do not influence heteromeric assembly with each other or with Cx26

Gemel

Lin

Veenstra

et al. 2006

Journal of Cell Science

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The cytoplasmic N-terminal domain in the connexins (Cx) has been implicated in determining several properties including connexin hetero-oligomerization, channel gating and regulation by polyamines. To elucidate the roles of potentially crucial amino acids, we produced site-directed mutants of connexins Cx40 and Cx43 (Cx40E12S,E13G and Cx43D12S,K13G) in which the charged amino acids at positions 12 and 13 were replaced with serine and glycine as found in Cx32. HeLa, N2a and HEK293 cells were transfected and studied by immunochemistry and double whole-cell patch clamping. Immunoblotting confirmed production of the mutant proteins, and immuno-fluorescence localized them to punctuate distributions along appositional membranes. Cx40E12S,E13G and Cx43D12S,K13G formed homotypic gap junction channels that allowed intercellular passage of Lucifer Yellow and electrical current, but these channels exhibited negligible voltage-dependent gating properties. Unlike wild-type Cx40, Cx40E12S,E13G channels were insensitive to block by 2 mM spermine. Affinity purification of material solubilized by Triton X-100 from cells co-expressing mutant Cx43 or mutant Cx40 with wild-type Cx40, Cx43 or Cx26 showed that introducing the mutations did not affect the compatibility or incompatibility of these proteins for heteromeric mixing. Co-expression of Cx40E12S,E13G with wild-type Cx40 or Cx43 dramatically reduced voltage-dependent gating. Thus, whereas the charged amino acids at positions 12 and 13 of Cx40 or Cx43 are not required for gap junction assembly or the compatibility of oligomerization with each other or with Cx26, they strongly influence several physiological properties including those of heteromeric channels.

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Developmental Regulation and Structural Organization of Connexins in Epidermal Gap Junctions

Cited by 79 publications

References 0 publications

Connexin43 and connexin26 form gap junctions, but not heteromeric channels in co-expressing cells

Connexin43 and connexin26 form gap junctions, but not heteromeric channels in co-expressing cells

Wounding alters epidermal connexin expression and gap junction-mediated intercellular communication.

N-terminal residues in Cx43 and Cx40 determine physiological properties of gap junction channels, but do not influence heteromeric assembly with each other or with Cx26

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