Genetic deletion of FRRS1L reduces the surface and total expression levels of GluA1 in cultured hippocampal neurons. (A) Screening candidate sgRNAs against FRRS1L in HEK cells. Western blotting analysis show that sgRNA#2 and sgRNA#3, but not sgRNA#1, strongly reduced FRRS1L-Myc expression in HEK cells, N = 3 independent repeats. Uncropped scans of Western blots were shown in Supplementary Figure 3. (B)
In situ hybridization (ISH) data show that sgRNA#3, but not sgRNA#1, eliminated Frrs1l mRNA expression (in red) in cultured hippocampal neurons (Control: score 3, n = 20; sgRNA#1: score 3, n = 15; sgRNA#3: score 0–1, n = 18). Scale bar, 10 μm. (C) sgRNA#3 induced genetic deletion of FRRS1L impaired sGluA1 and tGluA1 expressions in cultured hippocampal neurons. Representative dendrite images from a non-transfected control neuron or neurons expressing FRRS1L sgRNAs (Control: n = 11; sgRNA#1: n = 14; sgRNA#3: n = 13; normalized sGluA1: F (2,38) = 12.58, p < 0.0001; normalized tGluA1: F (2,38) = 16.74, p < 0.0001, sGluA1/tGluA1: F (2,38) = 9.27, p < 0.0001; one-way ANOVA with post hoc Fisher’s LSD test) are shown in the left panels. Scale bar, 20 μm.