Figure 3.

Synapsin phosphorylation sites are essential for STH formation. A, Schematic of synapsin protein with phosphorylation sites at S6 and S533 positions targeted for mutation. In the UAS-syn^ala-ala construct both serines are replaced by alanines (S6A, S533A). Domains A, C, and E are conserved in vertebrate synapsins. B, Validation of UAS-syn^ala-ala transgenic flies using S6-specific phospho-antibody (α-Psyn-S6). elav-Gal4> UAS-syn^ala-ala,syn⁹⁷/syn⁹⁷ flies (fourth lane in each blot) express a protein recognized by α-synapsin antibody (3C11), but not by α-Psyn-S6. C, α-Synapsin immunoreactivity in LN1 and GAD1 neurons with UAS-syn^ala-ala transgenic expression in syn⁹⁷ mutant background. D, Expression of synapsin with mutated motifs 1 and 2 in LN1 (LN1-Gal4> UAS-syn^ala-ala,syn⁹⁷/syn⁹⁷) or GABAergic neurons (GAD1-Gal4> UAS-syn^ala-ala,syn⁹⁷/syn⁹⁷) fails to rescue the syn⁹⁷ defect for STH. Before and after odorant exposure are represented as light gray and dark gray bars, respectively, along with mean ± SEM, N for each bar is 8–11 sets (Table 1). ***p < 0.001 (Student's t test with Bonferroni correction). WT, wild-type.