Anti-EIF4EBP1 (phospho T37 + T46) Antibody

A rabbit polyclonal IgG antibody from Antibodies.com that selectively recognizes EIF4EBP1 (also called 4E-BP1) only when it is phosphorylated at both threonine 37 and threonine 46. In resting cells, 4E-BP1 binds eIF4E and blocks cap-dependent translation; phosphorylation at T37 and T46 by mTOR is the priming step that permits subsequent phosphorylation at T70 and S65, releasing 4E-BP1 from eIF4E and switching on cap-dependent protein synthesis.

This dual-phospho specificity makes the reagent a useful readout for mTOR pathway activity, translational control, and signaling responses to growth factors, amino acids, or cellular stress in cell biology and cancer research workflows. The antibody is supplied as 100 µl of unconjugated serum, validated for Western blot, and shows reactivity against human, mouse, and rat samples, supporting both standard endpoint immunoblotting and stimulation or time-course experiments in cultured cells or tissue lysates.

The polyclonal host response increases the chance of robust signal even when one phospho-epitope is partially lost during sample handling, and the unconjugated IgG isotype allows flexible downstream labeling with HRP, fluorophore, or biotin conjugates of the researcher's choice. Typical applications include monitoring the T37/T46 phosphorylation status of 4E-BP1 as a downstream marker of mTORC1 signaling and correlating it with readouts of proliferation, autophagy, or metabolic state.