title: Pathological hemichannels associated with human Cx26 mutations causing Keratitis-Ichthyosis-Deafness syndrome.
abstract: Connexin (Cx) proteins form intercellular gap junction channels by first assembling into single membrane hemichannels that then dock to connect the cytoplasm of two adjacent cells. Gap junctions are highly specialized structures that allow the direct passage of small molecules between cells to maintain tissue homeostasis. Functional activity of nonjunctional hemichannels has now been shown in several experimental systems. Hemichannels may constitute an important diffusional exchange pathway with the extracellular space, but the extent of their normal physiological role is currently unknown. Aberrant hemichannel activity has been linked to mutations of connexin proteins involved in genetic diseases. Here, we review a proposed role for hemichannels in the pathogenesis of Keratitis-Ichthyosis-Deafness (KID) syndrome associated with connexin26 (Cx26) mutations. Continued functional evaluation of mutated hemichannels linked to human hereditary disorders may provide additional insights into the mechanisms governing their regulation in normal physiology and dysregulation in disease. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.
authors.affiliation: The Medical Scientist Training Program, Stony Brook University, Stony Brook, NY, USA.
authors.forename: Noah A
authors.initials: NA
authors.lastname: Levit
authors.forename: Gulistan
authors.initials: G
authors.lastname: Mese
authors.forename: Mena-George R
authors.initials: MG
authors.lastname: Basaly
authors.forename: Thomas W
authors.initials: TW
authors.lastname: White
mesh_terms: D000818:Animals; D001703:Biophysics / Q000379:methods; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D003593:Cytoplasm / Q000378:metabolism; D003638:Deafness / Q000235:genetics*; D017629:Gap Junctions / Q000502:physiology*; D006801:Humans; D007057:Ichthyosis / Q000235:genetics*; D007634:Keratitis / Q000235:genetics*; D008954:Models, Biological; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D009154:Mutation; D014981:Xenopus
chemical_list: D017630:Connexins; C000607045:GJB2 protein, Xenopus; C000607042:GJB2 protein, human; D000072259:Connexin 26