An in vitro CRISPR/Cas9-based functional screening of eIF4G2 target genes identified critical downstream effector of eIF4G2 regulation of plasma cell differentiation

Translational control plays a crucial role in the immune system, yet the key players, molecular mechanisms, and physiological functions remain poorly understood. We identified eukaryotic translation initiation factor 4G2 (eIF4G2) as a major regulator of internal ribosome entry site (IRES)-mediated translation during plasma cell differentiation. Mouse genetic studies confirmed the functional significance of eIF4G2 in plasma cell differentiation and antibody responses. To identify specific mRNAs whose translation initiation is regulated by eIF4G2 during plasma cell differentiation, we performed eCLIP-seq analysis of in vitro differentiated plasma cells and compiled a list of 663 eIF4G2 target genes. We then performed CRISPR/Cas9-mediated screening of those target genes to identify the ones mediating the function of eIF4G2.