Pou3f4^sdl

The mutation is a T to A transversion at nucleotide 900 (c.900T>A, NM_008901.1). The lesion within the coding region of the POU homeodomain was predicted to cause a premature stop codon at amino acid 300 out of 361 of the encoded peptide (p.Cys300*, NP_032927). Immunohistochemical analysis of mutant inner ears revealed that while mutant protein is present, it is mislocalized in the mesenchymal cells instead of the nuclei of the spiral ligament and spiral limbus. Thus, despite its presence in mutant cells in its truncated form, its cytoplasmic mislocalization most likely reflects lack of functionality. (J:220419)