CUBN Blocking Peptide – >85% Purity

Cubilin (CUBN) acts as a receptor for intrinsic factor-vitamin B12 complexes. The role of receptor is supported by the presence of 27 CUB domains. Cubulin is located within the epithelium of intestine and kidney. Mutations in CUBN may play a role in autosomal recessive megaloblastic anemia. [provided by RefSeq, Jul 2008]

CUBN: Cotransporter which plays a role in lipoprotein, vitamin and iron metabolism, by facilitating their uptake. Binds to ALB, MB, Kappa and lambda-light chains, TF, hemoglobin, GC, SCGB1A1, APOA1, high density lipoprotein, and the GIF-cobalamin complex. The binding of all ligands requires calcium. Serves as important transporter in several absorptive epithelia, including intestine, renal proximal tubules and embryonic yolk sac. Interaction with LRP2 mediates its trafficking throughout vesicles and facilitates the uptake of specific ligands like GC, hemoglobin, ALB, TF and SCGB1A1. Interaction with AMN controls its trafficking to the plasma membrane and facilitates endocytosis of ligands. May play an important role in the development of the peri-implantation embryo through internalization of APOA1 and cholesterol. Binds to LGALS3 at the maternal-fetal interface. Defects in CUBN are a cause of recessive hereditary megaloblastic anemia 1 (RH-MGA1); also known as MGA1 Norwegian type or Imerslund-Grasbeck syndrome (I-GS). RH-MGA1 is due to selective malabsorption of vitamin B12. Defects in vitamin B12 absorption lead to impaired function of thymidine synthase. As a consequence DNA synthesis is interrupted. Rapidly dividing cells involved in erythropoiesis are particularly affected.

Chromosomal Location of Human Ortholog: 10p12.31

Cellular Component: Golgi apparatus; lysosomal lumen; endoplasmic reticulum; lysosomal membrane; brush border membrane; coated pit; cytosol; extrinsic to external side of plasma membrane; membrane; endocytic vesicle; apical plasma membrane; plasma membrane; endosome membrane

Molecular Function: protein binding; protein homodimerization activity; transporter activity; calcium ion binding; receptor activity; cobalamin binding

Biological Process: steroid metabolic process; receptor-mediated endocytosis; cholesterol metabolic process; vitamin metabolic process; cobalamin metabolic process; lipoprotein transport; cobalamin transport; tissue homeostasis; lipoprotein metabolic process; water-soluble vitamin metabolic process; vitamin D metabolic process

Disease: Megaloblastic Anemia 1