Enables gap junction channel activity. Acts upstream of or within inner ear development. Predicted to be located in gap junction and plasma membrane. Predicted to be part of connexin complex. Is expressed in several structures, including cardiovascular system; fin; pleuroperitoneal region; sensory system; and xanthoblast. Human ortholog(s) of this gene implicated in several diseases, including Bart-Pumphrey syndrome; Vohwinkel syndrome; autosomal dominant keratitis-ichthyosis-deafness syndrome; ectodermal dysplasia (multiple); and nonsyndromic deafness (multiple). Orthologous to several human genes including GJB2 (gap junction protein beta 2).