Figure 6: The putative AKT phosphorylation site T10 in OSM-9 is required for H2O2-induced potentiation of sensory behavior and ASH function.
From: Promotion of behavior and neuronal function by reactive oxygen species in C. elegans
(a) Schematic of OSM-9 domain organization. Both the N and C-terminal fragments of OSM-9 are located intracellularly. Asterisks denote the putative AKT phosphorylation sites, with one at the N-terminus (T10) and the other four at the C-terminus (T769, T771, T787 and S839). These sites are predicted by Scansite. The N-terminal point mutation T10A is indicated. (b) The putative AKT phosphorylation site T10 in OSM-9 is required for H2O2-induced behavioral potentiation. osm-9(ky10) mutants failed to respond to glycerol stimulus. The basal response rate in the mutant arose from spontaneous reversal events that are present in the absence of glycerol stimulation. Wild-type and mutant forms of OSM-9 were expressed as transgenes in ASH neurons under the sra-6 promoter. Wild-type osm-9 transgene (ASH::osm-9), as well as osm-9 transgene with all the four putative C-terminal AKT sites mutated (that is ASH::osm-9(quad mutant)) rescued both the basal and H2O2-induced potentiation of osmotic avoidance response. However, osm-9 transgene harboring the point mutation T10A (that is ASH::osm-9(T10A)) failed to rescue H2O2-induced potentiation of osmotic avoidance response, though it rescued the basal avoidance behavior. n≥10; *P<0.05, **P<0.005 (ANOVA); Error bars: s.e.m. (c–f) The putative AKT phosphorylation site T10 in OSM-9 is required for H2O2-induced potentiation of ASH sensory response. In osm-9 mutant worms, ASH neurons did not respond to glycerol (c), and this defect was rescued by wild-type osm-9 transgene (d). Wild-type osm-9 transgene also rescued H2O2-induced potentiation of ASH sensory response (d). However, osm-9 transgene with the point mutation T10A (that is ASH::osm-9(T10A)) did not rescue H2O2-induced potentiation of ASH sensory response, though it rescued the basal glycerol sensory response in ASH neurons(e). Shades along the traces in (c–e) represent error bars (s.e.m.). Bar graph in (f) summarizes the data in (c–e). n≥8; Error bars: s.e.m. *P<0.05 (ANOVA).
