Fig. 6

CircMETTL9 interacts with SND1 protein in astrocytes. A Experimental procedure for protein pull-down by circMETTL9. First, circMETTL9 probe is biotinylated and added to lysate from LPS-stimulated astrocytes. Magnetic beads with bound streptavidin are then added to capture biotinylated probe and associated bound proteins. Finally, proteins are obtained by washing the magnetic beads. B KEGG pathway analysis of the top twenty enriched proteins bound to circMETTL9 according to mass spectrometry. C Overlap of proteins in catRAPID with Interaction Propensity > 70 and proteins with -10lgP > 70 by mass spectrometry (potential circMETTL9-interacting proteins). D Silver staining showing the presence of SND1. E Detection of SND1 by western blot after pull-down from astrocyte lysate by circMETTL9 probe but not negative probe. F Ion peak pattern showing the SND1 peptide, it is the secondary map of SND1 protein to a specific peptide. G Co-localization of SND1 (green) with circMETTL9 (red) in astrocyte cytoplasm by combined IF-FISH. Scale bar = 50 µm. H Representative western blots of SND1 expression in astrocytes after knockdown of circMETTL9. *P < 0.05, **P < 0.01, and ***P < 0.001 by one-way ANOVA