Figure 2.

MS analysis of enriched glomerular ECM fractions. (A) GO enrichment analysis of the full MS dataset. Nodes (circles) represent enriched GO terms, and edges (gray lines) represent overlap of proteins between GO terms. Node color indicates the significance of GO term enrichment; node diameter is proportional to the number of proteins assigned to each GO term. Edge weight is proportional to the number of proteins shared between connected GO terms. The full list of GO terms is detailed in Supplemental Figure 1. (B) All four protein fractions were analyzed by MS, and spectral counting was used to determine the enrichment of ECM proteins (identified by GO analysis). The mean ECM enrichment was 38% from three biologic replicates. (C) Relative quantification for the 10 most abundant ECM proteins detected by MS. Relative protein abundance was calculated using peptide intensity as described in Supplemental Methods. Gene names are shown for clarity, and collagen (COL) IV and laminin isoforms are combined as one value. (D) Western blotting (WB) confirmed enrichment of TINAGL1 and collagen VI in glomerular ECM.