TIF4631 Antibody

Biological Role of TIF4631

TIF4631 encodes the yeast homolog of mammalian eIF4G, a scaffolding protein essential for cap-dependent translation initiation . Key features include:

• Structural domains: RNA recognition motifs (RRMs) and auxiliary domains for binding eIF4E (cap-binding protein) and Pab1 (poly(A)-binding protein) .

• Functional redundancy: Shares 53% identity with TIF4632 (eIF4G2), its paralog, but exhibits distinct roles in translation efficiency and ribosome biogenesis .

• Essentiality: Single TIF4631 deletion causes slow growth and cold sensitivity, while double deletion with TIF4632 is lethal .

Applications of TIF4631 Antibody

The antibody is primarily used for:

• Western blotting: Detects endogenous TIF4631 in yeast lysates .

• Polysome profiling: Identifies translation initiation defects in tif4631Δ strains, such as reduced polysome/monosome ratios .

• Co-immunoprecipitation (Co-IP): Validates interactions with Pab1 and eIF4E .

Impact of TIF4631 Disruption on Translation

Interaction with Pab1

• TIF4631 binds Pab1 via a conserved 114-amino-acid region; mutations here (e.g., tif4631-213) reduce poly(A)-dependent translation by 7-fold in vitro .

• Deletion of the Pab1-binding domain (tif4631-ΔN300) abolishes ribosome recruitment to mRNAs with long poly(A) tails .

Antibody Specificity and Validation

• Isoform specificity: Generated using N-terminal peptides unique to TIF4631, enabling differentiation from TIF4632 .

• Cross-reactivity: Minimal with TIF4632, as confirmed by Western blot in tif4632Δ strains .

• Functional rescue: Exogenous TIF4631 expression restores wild-type polysome profiles in tif4631Δ mutants .

Therapeutic and Diagnostic Context

While monoclonal antibodies dominate therapeutic applications (e.g., COVID-19 treatments like sotrovimab ), TIF4631 antibodies remain confined to research. They are pivotal for studying:

• Translation dysregulation in yeast models of human diseases.

• Ribosome biogenesis pathways linked to cancer and neurodegeneration .

Technical Considerations

• Storage: Stable at -80°C in glycerol-based buffers.

• Dilution: Optimized at 1:1,000 for Western blotting .