The protein and the gene encoding the receptor for the cellular uptake of transcobalamin-bound cobalamin
| Autor: | Jeffrey M. Sequeira, Yasumi Nakayama, Edward V. Quadros |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Signal peptide
Placenta Molecular Sequence Data Immunology Receptors Cell Surface Biology Kidney Transfection Endocytosis Biochemistry Cell Line Cell membrane Red Cells Iron and Erythropoiesis Transcobalamin Affinity chromatography medicine Humans Amino Acid Sequence Gel electrophoresis Transcobalamins Cell Membrane Cell Biology Hematology Molecular biology Recombinant Proteins Protein Structure Tertiary Vitamin B 12 medicine.anatomical_structure Membrane protein LDL receptor Female Dimerization |
| Zdroj: | Blood. 113:186-192 |
| ISSN: | 1528-0020 0006-4971 |
| DOI: | 10.1182/blood-2008-05-158949 |
| Popis: | The transcobalamin (TC, TCII) receptor (TCblR) on the plasma membrane binds TC- cobalamin (Cbl) and internalizes the complex by endocytosis. This receptor was purified from human placental membranes by affinity chromatography. Tryptic digest of the protein extracted from a sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel and subjected to liquid chromatography/mass spectrometry identified 4 peptides that matched with a membrane protein in the data bank. TCblR belongs to the low-density lipoprotein receptor family, with 2 low-density lipoprotein receptor type A domains separated by a complement-like cysteine-rich region. The 282-amino acid sequence includes a signal peptide of 31 residues, extracellular domain of 198 residues, a transmembrane region of 21 residues, and a cytoplasmic domain of 32 residues. The binding of TC-Cbl does not require the cytoplasmic domain or its orientation in the plasma membrane because the recombinant extracellular domain binds TC-Cbl with high affinity and specificity. The protein is heavily glycosylated and accounts for the 58-kDa size by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The human gene first identified as 8D6A and more recently as CD 320 encoding TCblR is located at p13.2 on the short arm of chromosome 19, spans a length of 6.224 kb, and is composed of 5 exons and 4 introns. |
| Databáze: | OpenAIRE |
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