Fig. 1: Active CaMKII localizes to postsynaptic glutamate receptor fields and correlates with GluRIIA expression.
From: A glutamate receptor C-tail recruits CaMKII to suppress retrograde homeostatic signaling
A Schematic depicting the subunit composition of GluRA and GluRB glutamate receptor subtypes at the Drosophila NMJ. B Schematic and representative traces illustrate that postsynaptic expression of constitutively active CaMKII blocks the chronic expression of presynaptic homeostatic potentiation (PHP) that is normally induced by loss of the GluRIIA subunit. Genotypes: wild type (w1118); GluRIIA−/− (w;GluRIIASP16); G14 > CaMKIIT287D (w;G14-GAL4/+;UAS-CaMKIIT287D/+); G14 > CaMKIIT287D + GluRIIA−/− (w;G14-GAL4,GluRIIASP16/GluRIIASP16;UAS-CaMKIIT287D/+). (C) Quantification of mEPSP amplitude and quantal content values in the indicated genotypes normalized to baseline values (wild type: n = 10; GluRIIA−/−, n = 10, p < 0.0001 for mEPSP, p < 0.0001 for QC; G14 > CaMKIIT287D: n = 10; G14 > CaMKIIT287D + GluRIIA−/−: n = 10, p < 0.0001 for mEPSP, p = 0.072 for QC, unpaired, two-tailed t-test, with a significance value of 0.05). D Schematic of inactive and active versions of the CaMKII holoenzyme through phosphorylation of Thr-287. E CaMKII protein structure and the antigenic sites used to generate anti-CaMKII- and -pCaMKII- antibodies. Representative confocal images of the muscle 4 NMJ immunostained with anti-CaMKII or anti-pCaMKII antibodies and co-stained with either the postsynaptic scaffold Disks Large (DLG) or GluRIIA. F Representative images of NMJ boutons immunostained with anti-pCaMKII, -GluRIIA, -GluRIID, and -CaMKII in the indicated genotypes: GluRIIA-RNAi (w;G14-Gal4/+;UAS-GluRIIARNAi/+); GluRIIA-OE (w;+;MHC-GluRIIA). G Quantification of mean fluorescence intensity values of pCaMKII, GluRIIA, GluRIID, and CaMKII normalized to wild-type values in the indicated genotypes (wild type: n = 13; GluRIIA−/−, n = 12, p < 0.0001 for GluRIIA, p = 0.009 for pCaMKII, p = 0.9996 for GluRIID, p = 0.1497 for CaMKII; GluRIIA-RNAi: n = 10, p < 0.0001 for GluRIIA, p = 0.0080 for pCaMKII, p = 0.2027 for GluRIID, p = 0.1776 for CaMKII; GluRIIA-OE: n = 13, p < 0.0001 for GluRIIA, p < 0.0001 for pCaMKII, p = 0.9996 for GluRIID, p > 0.9999 for CaMKII). Repeated measures One-way ANOVA with Dunnett’s multiple comparisons test with a significance value of 0.05. p Value adjusted for multiple comparisons. Error bars indicate ±SEM. Asterisks indicate statistical significance using t-test or one-way ANOVA: **p < 0.01, ***p < 0.001, ****p < 0.0001; ns, not significant. n values indicate biologically independent NMJs. Absolute values for normalized data are summarized in Table S1. E, F Experiments were repeated four times independently with similar results. Source data are provided as a Source Data file.
