CD71; transferrin receptor 1; TfR1; TfR; TR; Trfr; T9; p90; sTfR (TFRC)
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Function
- internalizes iron into cells
- cellular uptake of iron occurs via receptor-mediated endocytosis of ligand-occupied transferrin receptor into specialized endosomes
- endosomal acidification leads to iron release
- the apotransferrin-receptor complex is then recycled to the cell surface with a return to neutral pH & the concomitant loss of affinity of apotransferrin for its receptor
- transferrin receptor is necessary for development of erythrocytes & the nervous system (putative)
- second ligand, the heditary hemochromatosis protein HFE, competes for binding with transferrin for an overlapping C-terminal binding site
- proteolytically cleaved on Arg-100 to produce the soluble serum form (sTfR)
- binds one transferrin or HFE molecule per subunit
- binds the HLA class II histocompatibility antigen, DR1
- interacts with SH3BP3
- phosphorylated
Structure
- N- & O-glycosylated, phosphorylated & palmitoylated
- serum form is only glycosylated
- palmitoylated on both Cys-62 & Cys-67; Cys-62 seems to be the major site of palmitoylation
- homodimer; disulfide-linked
- belongs to the peptidase M28 family, M28B subfamily
- contains 1 PA (protease associated) domain
Compartment
Expression
- translationally regulated by cellular iron levels through binding of iron regulatory proteins, IRP1 & IRP2, to iron-responsive elements in the 3'-UTR of TFRC mRNA
- up-regulated upon mitogenic stimulation
- expressed on most cells, especially, proliferating cells & cells requiring iron:
Pathology
expressed in AML M6
Laboratory
- serum transferrin receptor (sTfR) is used:
- as a means of detecting erythropoietin (EPO) misuse by athletes
- as a diagnostic test for anemia resulting from various conditions, including:
Comparative biology
- canine & feline parvoviruses bind human & feline transferrin receptors & use these receptors to enter & infect cells
More general terms
Additional terms
- serotransferrin; transferrin; Siderophilin; beta-1 metal-binding globulin (TF)
- transferrin receptor in serum
- transferrin receptor protein 2; TfR2 (TFR2)
References
- ↑ Luzio JP, Banting G. Eukaryotic membrane traffic: retrieval and retention mechanisms to achieve organelle residence. Trends Biochem Sci. 1993 Oct;18(10):395-8. Review. PMID: https://www.ncbi.nlm.nih.gov/pubmed/8256290
- ↑ Rimon E, Levy S, Sapir A, Gelzer G, Peled R, Ergas D, Sthoeger ZM. Diagnosis of iron deficiency anemia in the elderly by transferrin receptor-ferritin index. Arch Intern Med. 2002 Feb 25;162(4):445-9. <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/11863478
- ↑ <Internet> http://www.pathologyoutlines.com/cdmarkers.html 20 January 2003
- ↑ UniProt http://www.uniprot.org/uniprot/P02786.html