Identification of RNG140 (caprin2)-associated proteins in CHO cells

Regulation of gene expression at the translational level is key to determining cell fate and function. An RNA-binding protein RNG140 (caprin2) plays a role in cell differentiation such as eye lens development and has been reported to function in translational regulation. To identify RNG140-associated proteins, we generated CHO cells stably expressing GFP and RNG140-GFP, and performed immunoprecipitation (IP) with GFP antibody from those cells followed by mass spectrometry. We identified about 400 proteins specifically co-immunoprecipitated with RNG140-GFP but not with GFP. Gene ontology (GO) enrichment analysis revealed that the eIF3 subunit proteins and small ribosomal subunit proteins were significantly enriched in the RNG140-associated complex.