, 2007). When these transgenes are expressed under the control of elav-GAL4, Perry (G50A and G50R) and HMN7B (G38S) mutations this website cause a reduction in p150 protein expression in vivo compared with wild-type p150 expression, despite equivalent mRNA levels ( Figure 7C). These

data suggest that both HMN7B and Perry mutations cause the protein to be unstable, as is suggested by the reduced p150 protein levels we observe in GlG38S flies ( Figure 1D). We generated a high-level-expressing transgenic line (G38SHi) that expresses p150G38S mutant protein at levels at least as high, if not higher, than wild-type p150 ( Figure 7C), and this line was used to control for protein expression. Similar to what we observed in S2 cells and motor

neurons after expression of human p150G59S, when p150G38S-HA is expressed in motor neurons using the OK371-GAL4 driver, we find large puncta within motor neuron cell bodies, whereas p150WT-HA is diffusely present in the motor neuron cytoplasm ( Figures 7D and S8B). In the G38SHi line, all motor neurons show p150-HA(+) puncta, and many are very large ( Figures 7D and S8B); in the low-expressing line, however, large puncta are rarely observed (seen in at least two motor neurons in five out of six animals). Selleckchem BTK inhibitor In contrast, large puncta are not detected in p150G50A-HA or p150G50R-HA animals (no puncta seen in six animals each, Figures 7D and S8B). Because large puncta

were detected in p150G38S-HA animals that express lower levels of p150 protein (but equivalent mRNA levels) compared with p150G50A-HA or p150G50R-HA animals, we conclude that, within motor neurons, the HMN7B mutation makes p150 more aggregate prone than the Perry mutations. To determine whether Perry syndrome mutations and cause dynein-mislocalization phenotypes similar to those we observe in HMN7B (GlG38S) mutant animals, we overexpressed wild-type and mutant p150HA proteins in motor neurons. Overexpression of p150HA causes significant toxicity, similar to what we observed with high-level overexpression of untagged p150, as evidenced by a reduction in bouton number, abnormal synapse morphology, appearance of axonal swellings (data not shown), and accumulation of anti-HRP within the terminal bouton ( Figure 7E). However, we only observed TB accumulation of Dhc after p150G38S-HA overexpression ( Figures 6E and 6F); there was no difference in Dhc distribution among larvae overexpressing p150WT-HA, p150G50A-HA, or p150G50R-HA. Furthermore, motor neuron-specific expression of p150WT-HA, p150G50A-HA, and p150G50R-HA, but not p150G38S-HA, rescued the Dhc mislocalization phenotype observed in GlG38S/GlΔ22 animals ( Figure 7F).