Tyrosine codon 1815 in exon 31 (TAT) was changed to phenylalanine (TTT) (p.Y1815F) and a loxP site flanked neomycin resistance gene cassette was inserted into intron 31. The neo cassette was removed through Cre-mediated recombination. The mutation prevents phosphorylation of the residue in the encoded peptide. (J:314102)