The endogenous Pi3K92E promoter drives expression of a genomic fragment of Pi3K92E containing four mutations in the Ras-binding domain (RBD) of the Pi3K92E protein (amino acid replacements T231D, K250A, R253A and K257A), thereby abolishing its ability to bind the Ras85D protein. The mutant protein is tagged with Tag:MYC.
Pi3K92Et.RBD.Tag:MYC partially rescues Pi3K92EA
The P{Myc-Dp110RBD} transgene rescues Pi3K92EA lethality, as assayed in "Df(3R)Pi3K92EA, P{HBS}/Df(3R)Pi3K92EA" mutants. The rescued flies are fertile and produce viable offspring. P{Myc-Dp110RBD} also rescues Pi3K92EA lethality when Pi3K21B dosage is halved, as assayed in "Df(2L)Pi3K21B-A/+; Df(3R)Pi3K92EA, P{HBS}, P{U2af38.gR10}/Df(3R)Pi3K92EA" mutants.
Pi3K92EA homozygous null flies (genotype Df(3R)Pi3K92EA, P{HBS}) rescued with 2 copies of the P{Myc-Dp110RBD} transgene have wings approximately 86% of the area of control flies (Pi3K92EA homozygous null flies rescued with 2 copies of the P{Myc-Dp110} transgene), while their body mass is reduced to approximately 69% of controls.
Pi3K92EA homozygous null flies (genotype Df(3R)Pi3K92EA, P{HBS}) rescued with 2 copies of the P{Myc-Dp110RBD} transgene lay fewer eggs than controls (Pi3K92EA homozygous null flies rescued with 2 copies of the P{Myc-Dp110} transgene) at ages. Consistent with this, Pi3K92EA homozygous null flies rescued with 2 copies of P{Myc-Dp110RBD} have smaller ovaries with fewer ovarioles than controls.