Fig. 7.

Schematic representation of competition of eB-mediated shifts with 200-fold molar excess of unlabeled AD and ABD RNAs. The figure depicts the collective results of eB shift assays, competition shift assays, and mass spectroscopy protein identification of the sequence-specific shifts. The 14-3-3 protein family (β/α, ζ/δ, ε, η, and τ/θ), 40S and 60S ribosomal proteins, along with cytoskeletal proteins (actin and tubulin) bind directly or indirectly eB. Competition with molar excess of ABD gives rise to an altered eB mRNA-protein complex, which includes 14-3-3 ζ/δ, ε, γ, σ isoforms, L22 60S ribosomal protein, S27a 60S ribosomal protein, and actin; the rest of the proteins (including 14-3-3 isoforms β/α and τ/θ) are competed by the ABD probe. Competition with molar excess of AD results in a smaller eB mRNA-protein complex that includes L22 and L26 60S ribosomal proteins, S27a 60S ribosomal protein, eIF6, and actin; the rest of the proteins (including all of the 14-3-3 family of proteins) are competed with the AD probe.