Tyrosine codon 138 (TAT) in exon 5 was changed to leucine (TTG) (p.Y138L) and an FRT site flanked puromycin resistance gene cassette was inserted into intron 4. The puro cassette was removed through subsequent Flp-mediated recombination. The mutation leads to the encoded protein lacking protein phosphatase activity while leaving lipid phosphatase activity intact. (J:330701)