UASt regulatory sequences drive expression of a mutated form of brk, in which the CiM motif has been mutated from PMDLSLG to AMAAALA, the GiM motif has been mutated from FKPY to FAAA, amino acid residues 148-200 have been changed to two amino acid residues (RS). The protein is tagged at the C-terminal end with two copies of Tag:HA.