RESUMO
Objective To explore the deafness-causing underlying mechanisms of CX26 gene recessive mutations through functional analyzing nine missense mutations (p.S19T,p.R32H,p.E47K,p.V84L,p.V95M,p.R143W,p.R165W,p.S199F,p.L214P) in exogenous expression system Hela cells.Methods The nine recessive missense mutations of CX26,which are in the different domains of CX26 protein,and the wild type CX26 were subcloned into pEGFP-N1 vector directively,following to transfect into HeLa cells by the liposome complex method.The expressions of the mutated proteins were analyzed using western blot method.The localizations of the mutated proteins and whether there were gap junction-plaques formation were observed under confocal microscopy with immunofluorescence technique.Results The nine constructs were all expressed in HeLa cells.In which,the mutated proteins of p.S19T,p.E47K,p.V84L,p.V95M and p.R165W localized at the cytoplasmic membrane of HeLa cells and formed gap junction-plaques at contact points between two cells,and the mutated proteins of p.R32H,p.R143W,p.S199F and p.L214P accumulated and localized only intracellularly and did not form gap junction-plaques on cell membrenes.Conclusion The mutations of p.S19T,p.E47K,p.V84L,p.V95M and p.R165W do not interfere the mutated connxins trafficking and inserting into the plasma membrane.The mutations of p.R32H,p.R143W,p.S199F and p.L214P impared the proteins trafficking to the cell surface.The deafness-causing mechanisms of different missense mutations might not be identical and no correlation could be observed between the mutation and the topological domain of the mutated protein.