Phospho-4E-BP1 (Thr37/46) Recombinant Rabbit mAb (S-744-46)

Phospho-4E-BP1 (Thr37/46) refers to the specific modified form of eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) that has been phosphorylated at its threonine 37 and threonine 46 sites (Thr37/Thr46). 4E-BP1 is a key downstream effector protein of the mTORC1 signaling pathway, and its normal function is to act as a translation repressor: when in a hypophosphorylated state, it tightly binds to eukaryotic translation initiation factor 4E (eIF4E), preventing eIF4E from forming the initiation complex with eIF4G, thereby inhibiting the initiation of cap-dependent translation. However, when cells receive pro-growth signals such as growth factors, nutrients, or energy, the mTORC1 pathway is activated and preferentially catalyzes the phosphorylation of the Thr37 and Thr46 sites on the 4E-BP1 protein. This step is a foundational event for the "hyperphosphorylation" of 4E-BP1; it triggers a cascade of conformational changes in the protein, ultimately causing its dissociation from eIF4E. This release of eIF4E allows for the initiation of ribosome recruitment and protein synthesis. Therefore, detecting the level of Phospho-4E-BP1 (Thr37/46) serves as a highly sensitive and reliable molecular marker for gauging mTORC1 pathway activity. It is widely used as a key indicator in cancer research, metabolic diseases, and the study of cellular growth regulation to assess a cell's translational potential and proliferative status.