Figure 1
From: Constrained G4 structures unveil topology specificity of known and new G4 binding proteins
(A) Schematic representation of constrained DNA structures used in the pull-down assay. (B) Global strategy to identify constrained G4 interacting proteins from human cells. Biotin-functionalized G4-constrained molecules (1a and 2) and the biotin-functionalized duplex-DNA control 8 were individually mixed with a semi-total human protein extract from HeLa cells, then trapped by streptavidin magnetic beads to isolate interacting proteins. Protein identification was obtained from MS-based quantitative proteomic analysis and further characterized by western-blotting (arrow), or directly by western-blotting (dashed arrow). (C) Diagram showing the differential enrichment of human proteins on constrained G4 structures relative to control duplex DNA. G4 enriched proteins refer to proteins found enriched on 1a and/or 2 G4 constructions relative to the duplex control 8. 214 out of 425 proteins found enriched on constrained G4 have been shown to interact with nucleic acids. Differentially interacting proteins were sorted out using a fold change ≥ 2 and p-value < 0.05, allowing to reach a false discovery rate (FDR) inferior to 5% according to the Benjamini–Hochberg procedure.
