Gap-junctional channel and hemichannel activity of two recently identified connexin 26 mutants associated with deafness

作者：Dalamon Viviana; Fiori Mariana C; Figueroa Vania A; Oliva Carolina A; del Rio Rodrigo; Gonzalez Wendy; Canan Jonathan; Elgoyhen Ana B; Altenberg Guillermo A; Retamal Mauricio A^*

来源：Pflugers Archiv-European Journal of Physiology, 2016, 468(5): 909-918.

DOI：10.1007/s00424-016-1788-7

• Deafness
• Hemichannels
• Connexins
• Gap-junction channels
• Ion channel
• Mutation

Gap-junction channels (GJCs) are formed by head-to-head association of two hemichannels (HCs, connexin hexamers). HCs and GJCs are permeable to ions and hydrophilic molecules of up to Mr similar to 1 kDa. Hearing impairment of genetic origin is common, and mutations of connexin 26 (Cx26) are its major cause. We recently identified two novel Cx26 mutations in hearing-impaired subjects, L10P and G109V. L10P forms functional GJCs with slightly altered voltage dependence and HCs with decrease ATP/cationic dye selectivity. G109V does not form functional GJCs, but forms functional HCs with enhanced extracellular Ca2+ sensitivity and subtle alterations in voltage dependence and ATP/cationic dye selectivity. Deafness associated with G109V could result from decreased GJCs activity, whereas deafness associated to L10P may have a more complex mechanism that involves changes in HC permeability.

• 出版日期2016-5