Phospho-eIF4E (Ser209) antibody detects the phosphorylation of eukaryotic translation initiation factor 4E (eIF4E) at serine residue 209. a post-translational modification critical for regulating mRNA translation. eIF4E, a key component of the eIF4F complex, binds to the 5' cap structure of mRNAs to initiate cap-dependent translation. Its activity is tightly controlled by phosphorylation, primarily mediated by the MNK (MAP kinase-interacting kinase) kinases downstream of RAS-MAPK or PI3K-AKT signaling pathways. Phosphorylation at Ser209 enhances eIF4E’s affinity for the mRNA cap and promotes the selective translation of oncogenic mRNAs involved in cell proliferation, survival, and metastasis, such as c-Myc, VEGF, and cyclin D1. Dysregulation of eIF4E phosphorylation is linked to tumorigenesis, chemoresistance, and poor prognosis in cancers like leukemia, breast cancer, and glioblastoma.
The Phospho-eIF4E (Ser209) antibody is widely used in research to study translational control mechanisms, cellular stress responses, and cancer biology. It helps assess eIF4E activation status in experimental models, including drug-treated cells or tumor samples, and validates the efficacy of therapeutic agents targeting MNK kinases or upstream signaling pathways. Specificity is ensured by using synthetic peptides corresponding to the phosphorylated Ser209 epitope for immunization. Applications span Western blotting, immunoprecipitation, and immunofluorescence, enabling insights into eIF4E’s role in diseases and its potential as a biomarker or therapeutic target.