Exon 7 was modified to contain two nucleotide changes (CT to GG) that result in the amino acid substitution of alanine for glutamic acid at position 260 (E260A). A C-terminal hemagglutinin (HA) epitope tag (YPYDVPDY) was inserted. The IRES, MAPT (tau) and GFP reporter fusion was inserted into the 3' UTR. Flp-mediated recombination removed the FRT-flanked neomycin resistance cassette inserted downstream of the reporter fusion. (J:229180)