The M34A mutant of Connexin26 reveals active conductance states in pore-suspending membranes.
Connexin26 (Cx26) is a member of the connexin family, the building blocks for gap junction intercellular channels. These dodecameric assemblies are involved in gap junction-mediated cell-cell communication allowing the passage of ions and small molecules between two neighboring cells. Mutations in Cx26 lead to the disruption of gap junction-mediated intercellular communication with consequences such as hearing loss and skin disorders. We show here that a mutant of Cx26, M34A, forms an active hemichannel in lipid bilayer experiments. A comparison with the Cx26 wild-type is presented. Two different techniques using micro/nano-structured substrates for the formation of pore-suspending lipid membranes are used. We reconstituted the Cx26 wild-type and Cx26M34A into artificial lipid bilayers and observed single channel activity for each technique, with conductance levels of around 35, 70 and 165 pS for the wild-type. The conductance levels of Cx26M34A were found at around 45 and 70 pS.
Gassmann
Oliver
O
Institute for Organic and Biomolecular Chemistry, University of Göttingen, Germany.
Kreir
Mohamed
M
Ambrosi
Cinzia
C
Pranskevich
Jennifer
J
Oshima
Atsunori
A
Röling
Christian
C
Sosinsky
Gina
G
Fertig
Niels
N
Steinem
Claudia
C
D000818:Animals; D002460:Cell Line; D000072259:Connexin 26; D017630:Connexins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017629:Gap Junctions / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism*; D009154:Mutation; D051381:Rats
D017630:Connexins; C000607042:GJB2 protein, human; D008051:Lipid Bilayers; D000072259:Connexin 26