Transferrin Receptor 1 (TfR1)

Elemental iron is required for a variety of normal cellular functions and vital for proper growth and development. Transferrin (Tf), a serum glycoprotein of ~80kD and synthesized in the liver, is the primary protein of inter-organ transport of nonheme iron. Tf can bind two iron atoms. Tf binds to membrane Transferrin receptors (TfRs) and taken up by endocytosis. Iron is released from Tf, within acidic endosomes, into the cytoplasm apparently through the action of DMT1. The apoTf-TfR complex is returned to the cell surface, where, apo-Tf dissociates from TfR at the extracellular pH. The classical TfR, now TfR1, is a homodimeric (95kD subunits) type II membrane glycoprotein that binds two molecules of Tf. Human TfR1 has a cytoplasmic domain 1-67aa, 68-88 aa TM, and 89-760 aa as extracellular domains. A monomeric serum form or soluble TfR1 also exists that lacks residues 1-100 aa. Recently, a second Tf receptor, TfR2, has been cloned and characterized. TfR2 shares 45% identity with TfR1, and 27% with PMSA. Human TfR2 (human alpha 801 aa, Chromosome 7q22; mouse alpha 798 aa;) is predicted to contain a cytoplasmic domain of 1-80 aa, 1 TM domain followed by 105-801aa as the extracellular domain. It is highly expressed in liver and peripheral blood mononuclear cells. In contrast to Tfr1, expression of Tfr2 is not down regulated as a result of iron overload, consistent with the absence iron-responsive element in TfR2. It is alternatively spliced to alpha and beta isoforms. TfR2-beta protein lacked the N-terminal portion of the TfR2-alpha including the putative TM domain.\n\nApplications: Suitable for use in ELISA and Western Blot. Other applications not tested.\n\nRecommended Dilution:\nWestern Blot: 1:1000 ECL. \nELISA: 0.5-1ug/ml, use control peptide to coat wells at 1ug/ml.\nOptimal dilutions to be determined by the researcher.\nPositive control:\nT8199-43: Transferrin Receptor 1, Human, Western Blot Positive Control \nT8199-45: Transferrin Receptor 1, Human, Soluble, Control \n\nStorage and Stability:\nMay be stored at 4 degrees C for short-term only. For long-term storage, aliquot and store at -20 degrees C. Aliquots are stable for at least 12 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

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SPECIFICATIONS

Catalog Number

T8199-46

Size

50ug

Applications

ELISA, WB

Hosts

Mouse

Reactivities

Hum, Mouse, Rat, Ch/Bird

Form

Supplied as a liquid in PBS, pH 7.5, 0.1% BSA, 40% glycerol.

P Type

Mab

Purity

Purified by Protein A/G column chromatography.

Isotype

IgG1

References

1. Schneider, C., et al., Nature 311: 675-678 (1984). 2. McClelland, A., et al., Cell 39: 267-274 (1984). 3. Shih, Y.J., et al., JBC 265: 19077-19081 (1990). 4. Nelson, N., et al., EMBO J. 18: 4361-4371 (1999, review). 5. Cairo, G., Pietrangelo, A., et al., Biochem. J. 352: 241-250 (2000).

Additional Info

Epitope has been localized to the cytoplasmic N-terminus of human TfR1. This domain is missing is soluble TfR1. Species crossreactivity: Mouse, rat, chicken and hamster.