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Cubilin is a 460-kDa protein functioning as an endocytic receptor for intrinsic factor vitamin B(12) complex in the intestine and as a receptor for apolipoprotein A1 and albumin reabsorption in the kidney proximal tubules and the yolk sac. In the present study, we report the identification of cubilin as a novel transferrin (Tf) receptor involved in(More)
Steroid hormones are central regulators of a variety of biological processes. According to the free hormone hypothesis, steroids enter target cells by passive diffusion. However, recently we demonstrated that 25(OH) vitamin D(3) complexed to its plasma carrier, the vitamin D-binding protein, enters renal proximal tubules by receptor-mediated endocytosis.(More)
The present report shows the molecular characterization of the rat 460-kDa epithelial glycoprotein that functions as the receptor facilitating uptake of intrinsic factor-vitamin B12 complexes in the intestine and kidney. The same receptor represents also the yolk sac target for teratogenic antibodies causing fetal malformations in rats. Determination of its(More)
Receptor-mediated endocytosis is responsible for protein reabsorption in the proximal tubule. This process involves two interacting receptors, megalin and cubilin, which form a complex with amnionless. Whether these proteins function in parallel or as part of an integrated system is not well understood. Here, we report the renal effects of genetic ablation(More)
Cubilin is the intestinal receptor for the endocytosis of intrinsic factor-vitamin B12. However, several lines of evidence, including a high expression in kidney and yolk sac, indicate it may have additional functions. We isolated apolipoprotein A-I (apoA-I), the main protein of high-density lipoprotein (HDL), using cubilin affinity chromatography. Surface(More)
Cubilin and megalin are multiligand epithelial endocytic receptors well characterized in the adult kidney and ileum where they form a complex essential for protein, lipid and vitamin uptake. Although inactivation of the megalin gene leads to holoprosencephaly and administration of anti-cubilin antibodies induces fetal resorptions or cranio-facial(More)
Histiotrophic nutrition is essential during the peri-implantation development in rodents, but little is known about receptors involved in protein and lipid endocytosis derived from the endometrium and the uterine glands. Previous studies suggested that cubilin, a multiligand receptor for vitamin, iron, and protein uptake in the adult, might be important in(More)
Uptake of vitamin B12 (cyanocobalamin) is facilitated by the cobalamin-binder gastric intrinsic factor (IF), which recognizes a 460-kD receptor, cubilin, present in the epithelium of intestine and kidney. Surface plasmon resonance analysis of ligand-affinity-purified human cubilin demonstrated a high-affinity calcium- and cobalamin-dependent binding of(More)
BACKGROUND Several studies have indicated the central role of the megalin/cubilin multiligand endocytic receptor complex in protein reabsorption in the kidney proximal tubule. However, the poor viability of the existing megalin-deficient mice precludes further studies and comparison of homogeneous groups of mice. METHODS Megalin- and/or cubilin-deficient(More)
The molecular mechanisms controlling proximal tubule reabsorption of proteins have been much elucidated in recent years. Megalin and cubilin constitute two important endocytic receptor proteins involved in this process. Although structurally very different the two receptor proteins interact to mediate the reabsorption of a large number of filtered proteins,(More)