Your browser doesn't support javascript.
loading
A rare missense mutation in GJB3 (Cx31G45E) is associated with a unique cellular phenotype resulting in necrotic cell death.
Easton, Jennifer A; Albuloushi, Ahmad K; Kamps, Miriam A F; Brouns, Gladys H M R; Broers, Jos L V; Coull, Barry J; Oji, Vincent; van Geel, Michel; van Steensel, Maurice A M; Martin, Patricia E.
Afiliação
  • Easton JA; Department of Dermatology, Maastricht University Medical Centre, Maastricht, The Netherlands.
  • Albuloushi AK; GROW School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands.
  • Kamps MAF; Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, UK.
  • Brouns GHMR; Department of Dermatology, Maastricht University Medical Centre, Maastricht, The Netherlands.
  • Broers JLV; GROW School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands.
  • Coull BJ; Department of Genetics and Cell Biology, Maastricht University, Maastricht, The Netherlands.
  • Oji V; Department of Dermatology, Maastricht University Medical Centre, Maastricht, The Netherlands.
  • van Geel M; GROW School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands.
  • van Steensel MAM; Department of Genetics and Cell Biology, Maastricht University, Maastricht, The Netherlands.
  • Martin PE; Department of Dermatology, Maastricht University Medical Centre, Maastricht, The Netherlands.
Exp Dermatol ; 28(10): 1106-1113, 2019 10.
Article em En | MEDLINE | ID: mdl-29570224
Erythrokeratodermia variabilis et progressiva (EKV-P) is caused by mutations in either the GJB3 (Cx31) or GJB4 genes (Cx30.3). We identified a rare GJB3 missense mutation, c.134G>A (p.G45E), in two unrelated patients and investigated its cellular characteristics. Expression of Cx31G45E-GFP caused previously undescribed changes within HeLa cells and HaCaT cells, a model human keratinocyte cell line. Cx31WT-GFP localised to the plasma membrane, but expression of Cx31G45E-GFP caused vacuolar expansion of the endoplasmic reticulum (ER), the mutant protein accumulated within the ER membrane and disassembly of the microtubular network occurred. No ER stress responses were evoked. Cx31WT-myc-myc-6xHis and Cx31G45E-GFP co-immunoprecipitated, indicative of heteromeric interaction, but co-expression with Cx31WT-mCherry, Cx26 or Cx30.3 did not mitigate the phenotype. Cx31 and Cx31G45E both co-immunoprecipitated with Cx43, indicating the ability to form heteromeric connexons. WT-Cx31 and Cx43 assembled into large gap junction plaques at points of cell-to-cell contact; Cx31G45E restricted the ability of Cx43 to reach the plasma membrane in both HaCaT cells and HeLa cells stably expressing Cx43 where the proteins strongly co-localised with the vacolourised ER. Cell viability assays identified an increase in cell death in cells expressing Cx31G45E-GFP, which FACS analysis determined was necrotic. Blocking connexin channel function with 18α-glycyrrhetinic acid did not completely rescue necrosis or prevent propidium iodide uptake, suggesting that expression of Cx31G45E-GFP damages the cellular membrane independent of its channel function. Our data suggest that entrapment of Cx43 and necrotic cell death in the epidermis could underlie the EKV skin phenotype.
Assuntos
Palavras-chave

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Conexinas / Mutação de Sentido Incorreto / Eritroceratodermia Variável Tipo de estudo: Prognostic_studies / Risk_factors_studies Limite: Humans Idioma: En Ano de publicação: 2019 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Conexinas / Mutação de Sentido Incorreto / Eritroceratodermia Variável Tipo de estudo: Prognostic_studies / Risk_factors_studies Limite: Humans Idioma: En Ano de publicação: 2019 Tipo de documento: Article