Purification, properties, and immunochemical localization of a receptor for intrinsic factor-cobalamin complex in the rat kidney.

HDL: The Metabolism, Function, and Therapeutic Importance

“…179 Cubulin lacks a transmembrane domain and requires megalin for internalization. Initially identified as endocytic receptor for intrinsic factor-vitamin B12, 179,182 cubulin mediates HDL lipoprotein holoparticle endocytosis. 183 In yolk sac endoderm-like differentiated F9 cells that express high levels of cubulin, radiolabeled HDL was internalized and degraded in a cubulin-dependent manner.…”

Targeting the Cubilin Receptor through the Vitamin B12 Uptake Pathway: Cytotoxicity and Mechanistic Insight through Fluorescent Re(I) Delivery

“…IF is a 44 kDa glycosylated protein produced in gastric cells and has the highest specificity for B 12 ( K D ≈ 10 −9 ) , of the three binding proteins . IF is responsible for transport of B 12 across the intestinal enterocyte via the receptor, cubilin .…”

A Urinary Radioisotope‐Binding Assay to Diagnose Gräsbeck‐Imerslund Disease

“…This may involve either the synthesis or the expression of the receptor for the IF‐Cbl complex, or the intracellular trafficking of the cobalamin. It is possible that the disease consists of different subsets, as contradictory findings have been published concerning the cobalamin uptake in ileal biopsies from patients(4,9,10). Mackenzie et al suggested that the disease was caused by a defect of intracellular trafficking of cobalamin(28), and Burman et al said that it was the result of a defective uptake (29).…”

“…It is probably produced by proteolytic cleavage of the receptor for IF‐Cbl located in the epithelium of the kidney tubules (7). This urinary receptor is likely to be a part of the same protein expressed in the distal ileum(7‐10). However, the presence of the receptor in the kidney is teleologically puzzling, especially as there is more of it than in the intestine.…”