**Background of Cubilin Antibodies**
Cubilin, also known as the intrinsic factor-cobalamin receptor, is a multiligand endocytic receptor protein primarily expressed in polarized epithelial cells of the kidney, intestine, and yolk sac. It plays a critical role in nutrient absorption, particularly vitamin B12 (cobalamin) in the small intestine and protein reabsorption in the kidney proximal tubule. Structurally, cubilin lacks transmembrane domains and relies on interaction with megalin (LRP2) for cell surface anchorage and endocytic trafficking. Its large extracellular region contains multiple CUB domains, which mediate ligand binding to diverse molecules, including albumin, transferrin, and apolipoproteins.
Cubilin dysfunction is linked to genetic disorders like Imerslund-Gräsbeck syndrome (characterized by vitamin B12 deficiency and proteinuria) and acquired conditions such as chronic kidney disease. Research on cubilin antibodies has been pivotal in elucidating its physiological roles and pathological implications. These antibodies, often targeting specific CUB domains or epitopes, are utilized in techniques like Western blotting, immunohistochemistry, and immunofluorescence to study cubilin expression, localization, and interaction partners.
Recent studies also explore cubilin’s involvement in renal pathologies (e.g., diabetic nephropathy, IgA nephropathy) and cancer, where altered cubilin expression may influence disease progression. Therapeutic strategies targeting cubilin pathways, including antibody-based interventions, are under investigation for treating malabsorption syndromes or kidney disorders. Cubilin antibodies thus serve as essential tools for both basic research and clinical applications.