» Articles » PMID: 17182845

Transferrin Receptor 2: Evidence for Ligand-induced Stabilization and Redirection to a Recycling Pathway

Overview
Journal Mol Biol Cell
Date 2006 Dec 22
PMID 17182845
Citations 46
Authors
Affiliations
Soon will be listed here.
Abstract

Transferrin receptor 2 (TfR2) is a homologue of transferrin receptor 1 (TfR1), the protein that delivers iron to cells through receptor-mediated endocytosis of diferric transferrin (Fe(2)Tf). TfR2 also binds Fe(2)Tf, but it seems to function primarily in the regulation of systemic iron homeostasis. In contrast to TfR1, the trafficking of TfR2 within the cell has not been extensively characterized. Previously, we showed that Fe(2)Tf increases TfR2 stability, suggesting that trafficking of TfR2 may be regulated by interaction with its ligand. In the present study, therefore, we sought to identify the mode of TfR2 degradation, to characterize TfR2 trafficking, and to determine how Fe(2)Tf stabilizes TfR2. Stabilization of TfR2 by bafilomycin implies that TfR2 traffics to the lysosome for degradation. Confocal microscopy reveals that treatment of cells with Fe(2)Tf increases the fraction of TfR2 localizing to recycling endosomes and decreases the fraction of TfR2 localizing to late endosomes. Mutational analysis of TfR2 shows that the mutation G679A, which blocks TfR2 binding to Fe(2)Tf, increases the rate of receptor turnover and prevents stabilization by Fe(2)Tf, indicating a direct role of Fe(2)Tf in TfR2 stabilization. The mutation Y23A in the cytoplasmic domain of TfR2 inhibits its internalization and degradation, implicating YQRV as an endocytic motif.

Citing Articles

Dominant ARF3 variants disrupt Golgi integrity and cause a neurodevelopmental disorder recapitulated in zebrafish.

Fasano G, Muto V, Radio F, Venditti M, Mosaddeghzadeh N, Coppola S Nat Commun. 2022; 13(1):6841.

PMID: 36369169 PMC: 9652361. DOI: 10.1038/s41467-022-34354-x.


Transferrin receptor 2 (Tfr2) genetic deletion makes transfusion-independent a murine model of transfusion-dependent β-thalassemia.

Di Modica S, Tanzi E, Olivari V, Lidonnici M, Pettinato M, Pagani A Am J Hematol. 2022; 97(10):1324-1336.

PMID: 36071579 PMC: 9540808. DOI: 10.1002/ajh.26673.


Physiology and Inflammation Driven Pathophysiology of Iron Homeostasis-Mechanistic Insights into Anemia of Inflammation and Its Treatment.

Lanser L, Fuchs D, Kurz K, Weiss G Nutrients. 2021; 13(11).

PMID: 34835988 PMC: 8619077. DOI: 10.3390/nu13113732.


Coordination of iron homeostasis by bone morphogenetic proteins: Current understanding and unanswered questions.

Fisher A, Babitt J Dev Dyn. 2021; 251(1):26-46.

PMID: 33993583 PMC: 8594283. DOI: 10.1002/dvdy.372.


Transferrin Receptors in Erythropoiesis.

Richard C, Verdier F Int J Mol Sci. 2020; 21(24).

PMID: 33352721 PMC: 7766611. DOI: 10.3390/ijms21249713.


References
1.
Laemmli U . Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970; 227(5259):680-5. DOI: 10.1038/227680a0. View

2.
Bowman E, Siebers A, Altendorf K . Bafilomycins: a class of inhibitors of membrane ATPases from microorganisms, animal cells, and plant cells. Proc Natl Acad Sci U S A. 1988; 85(21):7972-6. PMC: 282335. DOI: 10.1073/pnas.85.21.7972. View

3.
Roetto A, Papanikolaou G, Politou M, Alberti F, Girelli D, Christakis J . Mutant antimicrobial peptide hepcidin is associated with severe juvenile hemochromatosis. Nat Genet. 2002; 33(1):21-2. DOI: 10.1038/ng1053. View

4.
Nemeth E, Roetto A, Garozzo G, Ganz T, Camaschella C . Hepcidin is decreased in TFR2 hemochromatosis. Blood. 2004; 105(4):1803-6. DOI: 10.1182/blood-2004-08-3042. View

5.
Fleming R, Migas M, Holden C, Waheed A, Britton R, Tomatsu S . Transferrin receptor 2: continued expression in mouse liver in the face of iron overload and in hereditary hemochromatosis. Proc Natl Acad Sci U S A. 2000; 97(5):2214-9. PMC: 15780. DOI: 10.1073/pnas.040548097. View