Cobalamin transport proteins and their cell-surface receptors.

Article Details

Citation

Seetharam B, Yammani RR

Cobalamin transport proteins and their cell-surface receptors.

Expert Rev Mol Med. 2003 Jun 13;5(18):1-18.

PubMed ID
14585166 [ View in PubMed
]
Abstract

The primary function of cobalamin (Cbl; vitamin B12) is the formation of red blood cells and the maintenance of a healthy nervous system. Before cells can utilise dietary Cbl, the vitamin must undergo cellular transport using two distinct receptor-mediated events. First, dietary Cbl bound to gastric intrinsic factor (IF) is taken up from the apical pole of ileal epithelial cells via a 460 kDa receptor, cubilin, and is transported across the cell bound to another Cbl-binding protein, transcobalamin II (TC II). Second, plasma TC II-Cbl is taken up by cells that need Cbl via the TC II receptor (TC II-R), a 62 kDa protein that is expressed as a functional dimer in cellular plasma membranes. Human Cbl deficiency can develop as a result of acquired or inherited dysfunction in either of these two transmembrane transport events. This review focuses on the biochemical, cellular and molecular aspects of IF and TC II and their cell-surface receptors.

DrugBank Data that Cites this Article

Drugs
Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
HydroxocobalaminCubilinProteinHumans
Unknown
Other
Details
HydroxocobalaminProtein amnionlessProteinHumans
Unknown
Other
Details
Drug Carriers
DrugCarrierKindOrganismPharmacological ActionActions
HydroxocobalaminTranscobalamin-2ProteinHumans
Unknown
Substrate
Details