Opposing modulation of Cx26 gap junctions and hemichannels by CO2.
This article is protected by copyright. All rights reserved. PMID: 33022747 [PubMed - as supplied by publisher]
Conclusions: Multimodal imaging including in vivo confocal microscopy suggests that dysfunctional corneal basal epithelium maturation might contribute to the pathophysiology of keratopathy in KID syndrome.
LE, Alba-Rojas E PMID: 32627836 [PubMed - as supplied by publisher]
We describe unrelated subjects with ichthyosis, failure to thrive, thrombocytopenia, hearing loss, and profound photophobia, progressing to complete deafness and near-complete blindness in one subject. Exome sequencing reveals that each have novel and deleterious biallelic mutations in AP1B1, the gene encoding the β subunit of heterotetrameric adapter protein 1 (AP-1) complexes. There are two types of AP-1 complex, ubiquitous AP-1A and epithelium-specific AP-1B, which function in clathrin-coated vesicle budding within the trans-Golgi network and endosomes and in polarized transport of proteins to the basolat eral membrane.
AbstractCongenital diarrheal disorders (CDD) comprise > 50 monogenic entities featuring chronic diarrhea of early-onset, including defects in nutrient and electrolyte absorption, enterocyte polarization, enteroendocrine cell differentiation, and epithelial integrity. Diarrhea is also a predominant symptom in many immunodeficiencies, congenital disorde rs of glycosylation, and in some defects of the vesicular sorting and transporting machinery. We set out to identify the etiology of an intractable diarrhea in 2 consanguineous families by whole-exome sequencing, and identified two novelAP1S1 mutations, c.2...
Keratitis-ichthyosis-deafness (KID) syndrome is a severe, untreatable condition characterized by ocular, auditory and cutaneous abnormalities, with major complications of infection and skin cancer. 86% of cases are caused by a heterozygous missense mutation (c.148G>A, p.D50N) in the GJB2 gene, encoding gap junction protein connexin 26 (Cx26), which alters gating properties of Cx26 channels in a dominant manner. We hypothesized that a mutant-allele-specific siRNA (AS-siRNA) could rescue the cellular phenotype in patient keratinocytes.
Keratitis-ichthyosis-deafness (KID) syndrome is a severe, untreatable condition characterized by ocular, auditory, and cutaneous abnormalities, with major complications of infection and skin cancer. Most cases of KID syndrome (86%) are caused by a heterozygous missense mutation (c.148G>A, p.D50N) in the GJB2 gene, encoding gap junction protein Cx26, which alters gating properties of Cx26 channels in a dominant manner. We hypothesized that a mutant allele-specific small interfering RNA could rescue the cellular phenotype in patient keratinocytes (KCs).
MEDNIK syndrome (mental retardation, enteropathy, deafness, peripheral neuropathy, ichthyosis, and keratoderma) is an autosomal-recessive disorder caused by bi-allelic mutations in AP1S1, encoding the small σ subunit of the AP-1 complex. Central to the pathogenesis of MEDNIK syndrome is abnormal AP-1-mediated trafficking of copper transporters; this abnormal trafficking results in a hybrid phenotype combining the copper-deficiency-related characteristics of Menkes disease and the copper-toxicity-relat ed characteristics of Wilson disease.
We describe unrelated individuals with ichthyosis, failure to thrive, thrombocytopenia, photophobia, and progressive hearing loss. Each have bi-allelic mutations in AP1B1, the gene encoding the β subunit of heterotetrameric adaptor protein 1 (AP-1) complexes, which mediate endomembrane polarization, sorting, and transport. In affected keratinocytes the AP-1 β subunit is lost, and the γ subunit is greatly reduced, demonstrating destabilization of the AP-1 complex. Affected cells and tiss ue contain an abundance of abnormal vesicles and show hyperproliferation, abnormal epidermal differentiation, and derangem...
A 14-year-old girl with a history of keratitis-ichthyosis-deafness (KID) syndrome, a rare autosomal dominant condition, was referred to the Department of Plastic Surgery at Brussels University Hospital in June 2016 for progressively worsening inguinoperineal ulceration exacerbated by overapplication of combination drug treclinax (tretinoin and erythromycin). On assessment, a large area of purulent papillomatous hyperkeratosis with follicular plugging, likely superimposed bacterial colonization, and deep ulceration were noted requiring thorough debridement. A first procedure was performed in June 2016 with hydrosurgical de...
Germline missense mutations in GJB2 encoding connexin (Cx) 26 have been found in keratitis, ichthyosis and deafness (KID) syndrome. We explored the effects of three mouse Cx26 mutants (Cx26-G12R, -G45E and -D50N) corresponding to KID syndrome-causative human mutants on hemichannel activities leading to cell death and the expression of immune response-associated genes. We analyzed the 3D images of cells expressing wild-type (WT) or mutant Cx26 molecules to demonstrate clearly the intracellular localization of Cx26 mutants and hemichannel formation.