Anti-Phospho-eIF4EBP1-S65 Rabbit Polyclonal Antibody for WB, ELISA - Q13541

Core Product Specifications and Parameters

Biological Background: eIF4EBP1 Function and Localization

• eIF4EBP1 (Eukaryotic translation initiation factor 4E-binding protein 1), also known as PHAS-I (phosphorylated heat- and acid-stable protein regulated by insulin 1), is a key repressor of cap-dependent translation initiation.
• In its hypophosphorylated state, 4E-BP1 competes with eIF4G for binding to eIF4E, thereby preventing assembly of the eIF4F complex and inhibiting translation. Hyperphosphorylation, such as at Ser65, promotes dissociation from eIF4E, allowing cap-dependent translation to proceed.
• 4E-BP1 integrates signals from growth factors, hormones, and nutrients via the MAP kinase and mTORC1 pathways, with mTORC1-mediated phosphorylation at multiple sites (including Thr37/46, Ser65, and Thr70) being critical for its inactivation.
• 4E-BP1 belongs to the eIF4E-binding protein family and shares a conserved eIF4E-binding motif (YXXXXLΦ) that directly interacts with the dorsal surface of eIF4E.
• Subcellular localization is primarily cytoplasmic, but 4E-BP1 can shuttle to the nucleus, where it may regulate nuclear translation or other functions. Compartmentalized phosphorylation dynamics may vary.
• In addition to phosphorylation, 4E-BP1 undergoes acetylation, ubiquitination (isopeptide bond formation), and other post-translational modifications that fine-tune its stability and activity, classifying it as a phosphoprotein and a target of ubiquitin-like conjugation.

Experimental Guidance and Technical Tips

• The immunogen is a synthetic phosphorylated peptide surrounding Ser65, so the antibody’s reactivity is expected to be phospho-specific. For ELISA, consider pre-incubating the antibody with a non-phosphorylated peptide to confirm phospho-specificity.
• In western blotting, include total 4E-BP1 detection (using a pan antibody) to monitor both total protein levels and phosphorylation status. Use appropriate phosphatase inhibitors in lysis buffers.
• The antibody recognizes human 4E-BP1. Validate performance in human cell lines or tissue samples; reactivity with other species has not been reported so cross-reactivity testing is advised if applied to non-human samples.
• As a polyclonal rabbit antibody, lot-to-lot consistency should be monitored; pilot experiments with the specific lot are recommended.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio empowers diagnostic manufacturers and translational research teams with consolidated access to IVD raw materials, from validated antibody pairs and optimized phospho-specific antibodies to bulk ancillary reagents. For mTORC1 signaling and translation initiation research, we offer high-quality reagents such as Anti-Phospho-eIF4EBP1-S65, alongside rare-target raw-material sourcing and technical consultation—helping you streamline development from discovery to clinical application.