Figure 6.

Chemical Cross-Linking Identifies Proteins of the Core RBP50–RNP Complex.

Phloem proteins (Input) were coimmunoprecipitated using either preimmune serum (Pre) or purified RBP50 antibody. Isolated RBP50–RNP complexes were then treated with the chemical cross-linker, bis(sulfosuccinimidyl) suberate, and subjected to SDS-PAGE. Protein profiles were visualized using GBS reagent (left panel). To confirm the cross-linkage of RBP50 with its interacting proteins, protein gel blot assays were performed using purified anti-RBP50 antibody (middle panel) or purified anti-PP16-1 antibody (right panel). Asterisks (left panel) indicate protein bands that underwent changes in intensity after cross-linker treatment. The boxed regions on the SDS-PAGE gel were excised for protein analysis using LC-MS/MS.