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CD71; transferrin receptor 1; TfR1; TfR; TR; Trfr; T9; p90; sTfR (TFRC)
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:
- cell membrane
- melanosome
- secreted
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:
a) reticulocytes
b) erythroid precursors
c) capillary endothelium in brain
Pathology: expressed in AML M6
Laboratory:
- serum transferrin receptor (sTfR) is used:
a) as a means of detecting erythropoietin (EPO) misuse by athletes
b) as a diagnostic test for anemia resulting from various conditions, including:
1] rheumatoid arthritis
2] pregnancy
3] irritable bowel syndrome
4] HIV patients
Comparative biology:
- canine & feline parvoviruses bind human & feline transferrin receptors & use these receptors to enter & infect cells
Interactions
molecular events
Related
CD71 cells in blood
serotransferrin; transferrin; Siderophilin; beta-1 metal-binding globulin (TF)
transferrin receptor in serum
transferrin receptor protein 2; TfR2 (TFR2)
General
cluster-of-differentiation antigen; cluster designation antigen; CD antigen
cell surface receptor
glycoprotein
phosphoprotein
Properties
SIZE: entity length = 760 aa
MW = 85 kD
COMPARTMENT: cellular membrane
MOTIF: SH3BP4 interaction {1-67}
MOTIF: Endocytosis signal {20-23}
Tyr phosphorylation site {Y20}
Ser phosphorylation site {S24}
stop-transfer {58-61}
cysteine residue {C62}
MODIFICATION: palmitate
COMPARTMENT: membrane
cysteine residue {C67}
MODIFICATION: palmitate
COMPARTMENT: membrane
transmembrane domain {68-88}
cysteine residue {C89}
MODIFICATION: cysteine residue {C-INTERCHAIN}
cysteine residue {C98}
MODIFICATION: cysteine residue {C-INTERCHAIN}
cleavage {100-101}
Thr glycosylation site {T104}
PA {223-313}
MOTIF: N-glycosylation site {N251}
N-glycosylation site {N317}
binding site
SITE: 569-760
FOR-BINDING-OF: serotransferrin
MOTIF: cell attachment {646-648}
N-glycosylation site {N727}
Database Correlations
OMIM 190010
UniProt P02786
PFAM correlations
Kegg hsa:7037
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: 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.
PMID: 11863478
- http://www.pathologyoutlines.com/cdmarkers.html
20 January 2003
- UniProt :accession P02786
Component-of
molecular complex