Cobalamin transport proteins and their cell-surface receptors
| Autor: | Bellur Seetharam, Raghunatha R. Yammani |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Intrinsic Factor
Transcobalamins Intrinsic factor Cobalamin transport Cell Membrane fungi Receptors Cell Surface Vitamin B 12 Deficiency Membrane transport Cubilin Endocytosis Cobalamin Structure-Activity Relationship Vitamin B 12 chemistry.chemical_compound Intestinal Absorption chemistry Biochemistry Cell surface receptor hemic and lymphatic diseases Humans Molecular Medicine Receptor Molecular Biology |
| Zdroj: | Expert Reviews in Molecular Medicine. 5:1-18 |
| ISSN: | 1462-3994 |
| DOI: | 10.1017/s1462399403006422 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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