UASt regulatory sequences drive expression of a mutant form of Rab3 in which amino acid residues 189-190 are mutated from SL to AA (these two residues have been reported to interact with Rabphilin). This is predicted to disrupt interactions that involve the third complementarity-determining region (CDR).
Expression of Rab3L189-190AA.Scer\UAS driven by Scer\GAL4VGlut.PD rescues active zone defects at the NMJ of Rab3rup/Df(2R)ED2076 third instar larvae.