Polymorphism of the 86th amino acid in CX26 protein and hereditary deafness

Objective: To investigate the membrane localization function of the CX26 protein when its 86 th amino acid is Thr, Ser or Arg, and its relations to deafness.Methods: CX26-GFP protein with either Thr, Ser or Arg as the 86 th amino acid was expressed in mouse SGN cells via the GFP fusion type lentivirus expression system. The membrane localization of the fusion protein was observed under a fluorescence microscope.Results: The mutated protein of CX26 T86 S was localized to cell membrane and form gap conjunction structures, showing no difference to the wild type CX26 protein(with Thr as the 86 th amino acid). However, the gap conjunction structure disappeared when the mutation was CX26T86 A.Conclusion: These results indicate that the CX26 T86 R mutation may be a cause of hearing loss, but CX26 T86 S as a non-pathogenic polymorphism mutation does not affect functions of the CX26 protein. The results are in accordance with the results of clinical screening.