Transferrin‐Directed Internalization and Cycling of Transferrin Receptor 2

Transferrin receptor 2 (TfR2) is a homologue of transferrin receptor 1 (TfR1) but has distinct functions from TfR1 in iron homeostasis. In keeping with its proposed role in iron sensing, previous studies showed that TfR2 has a short half‐life and that holo‐Tf stabilizes TfR2 by redirecting it from a degradative pathway to a recycling pathway. In this study, we characterized how the endocytosis, recycling and degradation of TfR2 relates to its function and differs from TfR1. TfR2 endocytosis was adaptor protein‐2 (AP‐2) dependent. Flow cytometry analysis showed that TfR1 and TfR2 utilized the same endocytic pathway only in the presence of holo‐Tf, indicating that holo‐Tf alters the interaction of TfR2 with the endocytic machinery. Unlike TfR1, phosphofurin acidic cluster sorting protein 1 (PACS‐1) binds to the cytoplasmic domain of TfR2 and data suggest that PACS‐1 is involved in the TfR2 recycling. Depletion of TSG101 by siRNA or expression of a dominant negative Vps4 inhibited TfR2 degradation, indicating that TfR2 degradation occurs through a multivesicular body (MVB) pathway. TfR2 degradation is not mediated through ubiquitination on the single lysine (K31) in the cytoplasmic domain or on the amino terminal residue. No ubiquitination of TfR2 by HA‐ubiquitin was detected, indicating a lack of direct TfR2 ubiquitination involvement in its degradation.

[1]  H. Tsukamoto,et al.  Interaction of the hereditary hemochromatosis protein HFE with transferrin receptor 2 is required for transferrin-induced hepcidin expression. , 2009, Cell metabolism.

[2]  Ishara F Azmi,et al.  Regulation of Vps4 ATPase activity by ESCRT-III. , 2009, Biochemical Society transactions.

[3]  Anna M. Keller,et al.  Apoptosis induction by Bid requires unconventional ubiquitination and degradation of its N-terminal fragment , 2007, The Journal of cell biology.

[4]  G. Schiavo,et al.  Neurotrophins Redirect p75NTR from a Clathrin‐Independent to a Clathrin‐Dependent Endocytic Pathway Coupled to Axonal Transport , 2007, Traffic.

[5]  A. Brech,et al.  Vps22/EAP30 in ESCRT‐II Mediates Endosomal Sorting of Growth Factor and Chemokine Receptors Destined for Lysosomal Degradation , 2007, Traffic.

[6]  J. Bonifacino,et al.  Direct binding to Rsp5p regulates ubiquitination-independent vacuolar transport of Sna3p. , 2007, Molecular biology of the cell.

[7]  C. Enns,et al.  The Cytoplasmic Domain of Transferrin Receptor 2 Dictates Its Stability and Response to Holo-transferrin in Hep3B Cells* , 2007, Journal of Biological Chemistry.

[8]  C. Enns,et al.  Transferrin receptor 2: evidence for ligand-induced stabilization and redirection to a recycling pathway. , 2007, Molecular biology of the cell.

[9]  M. Aboian,et al.  Characterization of multiple multivesicular body sorting determinants within Sna3: a role for the ubiquitin ligase Rsp5. , 2006, Molecular biology of the cell.

[10]  Matthew West,et al.  Direct binding to Rsp5 mediates ubiquitin-independent sorting of Sna3 via the multivesicular body pathway. , 2006, Molecular Biology of the Cell.

[11]  W. Stremmel,et al.  Localization of the iron-regulatory proteins hemojuvelin and transferrin receptor 2 to the basolateral membrane domain of hepatocytes , 2007, Histochemistry and Cell Biology.

[12]  C. Peschle,et al.  TfR2 localizes in lipid raft domains and is released in exosomes to activate signal transduction along the MAPK pathway , 2006, Journal of Cell Science.

[13]  G. Thomas,et al.  A PACS‐1, GGA3 and CK2 complex regulates CI‐MPR trafficking , 2006, The EMBO journal.

[14]  Y. Henis,et al.  Different Routes of Bone Morphogenic Protein (BMP) Receptor Endocytosis Influence BMP Signaling , 2006, Molecular and Cellular Biology.

[15]  C. Futter,et al.  Distinct roles for Tsg101 and Hrs in multivesicular body formation and inward vesiculation. , 2006, Molecular biology of the cell.

[16]  G. Lukács,et al.  The ESCRT-III subunit hVps24 is required for degradation but not silencing of the epidermal growth factor receptor. , 2006, Molecular biology of the cell.

[17]  Scott D Emr,et al.  The ESCRT complexes: structure and mechanism of a membrane-trafficking network. , 2006, Annual review of biophysics and biomolecular structure.

[18]  G. Raposo,et al.  A lumenal domain-dependent pathway for sorting to intralumenal vesicles of multivesicular endosomes involved in organelle morphogenesis. , 2006, Developmental cell.

[19]  C. Tacchetti,et al.  TTP Specifically Regulates the Internalization of the Transferrin Receptor , 2005, Cell.

[20]  P. Woodman,et al.  Depletion of TSG101 forms a mammalian `Class E' compartment: a multicisternal early endosome with multiple sorting defects , 2005, Journal of Cell Science.

[21]  K. Cadwell,et al.  Ubiquitination on Nonlysine Residues by a Viral E3 Ubiquitin Ligase , 2005, Science.

[22]  Jerry Kaplan,et al.  Hepcidin Regulates Cellular Iron Efflux by Binding to Ferroportin and Inducing Its Internalization , 2004, Science.

[23]  C. Enns,et al.  Diferric transferrin regulates transferrin receptor 2 protein stability. , 2004, Blood.

[24]  M. Wessling-Resnick,et al.  Regulation of transferrin receptor 2 protein levels by transferrin. , 2004, Blood.

[25]  S. Sugai,et al.  Analyses for binding of the transferrin family of proteins to the transferrin receptor 2 , 2004, British journal of haematology.

[26]  M. Ericsson,et al.  Transferrin receptor 2 mediates a biphasic pattern of transferrin uptake associated with ligand delivery to multivesicular bodies. , 2004, American journal of physiology. Cell physiology.

[27]  M. von Zastrow,et al.  Role of Mammalian Vacuolar Protein-sorting Proteins in Endocytic Trafficking of a Non-ubiquitinated G Protein-coupled Receptor to Lysosomes* , 2004, Journal of Biological Chemistry.

[28]  Jean Gruenberg,et al.  The biogenesis of multivesicular endosomes , 2004, Nature Reviews Molecular Cell Biology.

[29]  J. Klumperman,et al.  ATPase-deficient hVPS4 impairs formation of internal endosomal vesicles and stabilizes bilayered clathrin coats on endosomal vacuoles , 2004, Journal of Cell Science.

[30]  A. Ciechanover,et al.  N-terminal ubiquitination: more protein substrates join in. , 2004, Trends in cell biology.

[31]  M. J. Clague,et al.  Hrs function: viruses provide the clue. , 2003, Trends in cell biology.

[32]  F. Gu,et al.  The phosphorylation state of an autoregulatory domain controls PACS‐1‐directed protein traffic , 2003, The EMBO journal.

[33]  M. Pagano,et al.  Proteasome-Mediated Degradation of p21 via N-Terminal Ubiquitinylation , 2003, Cell.

[34]  A. Motley,et al.  Clathrin-mediated endocytosis in AP-2–depleted cells , 2003, The Journal of cell biology.

[35]  P. Bjorkman,et al.  Heterotypic interactions between transferrin receptor and transferrin receptor 2. , 2003, Blood.

[36]  S. Emr,et al.  Receptor downregulation and multivesicular-body sorting , 2002, Nature Reviews Molecular Cell Biology.

[37]  P. Oates,et al.  IEC-6 cells are an appropriate model of intestinal iron absorption in rats. , 2002, The Journal of nutrition.

[38]  Wesley I. Sundquist,et al.  Tsg101 and the Vacuolar Protein Sorting Pathway Are Essential for HIV-1 Budding , 2001, Cell.

[39]  Fulvio Reggiori,et al.  Sorting of proteins into multivesicular bodies: ubiquitin‐dependent and ‐independent targeting , 2001, The EMBO journal.

[40]  S. Emr,et al.  Ubiquitin-Dependent Sorting into the Multivesicular Body Pathway Requires the Function of a Conserved Endosomal Protein Sorting Complex, ESCRT-I , 2001, Cell.

[41]  F. Gu,et al.  PACS‐1 binding to adaptors is required for acidic cluster motif‐mediated protein traffic , 2001, The EMBO journal.

[42]  A. Ciechanover,et al.  Degradation of the E7 human papillomavirus oncoprotein by the ubiquitin-proteasome system: targeting via ubiquitination of the N-terminal residue , 2000, Oncogene.

[43]  A. Ciechanover,et al.  Degradation of the Epstein-Barr Virus Latent Membrane Protein 1 (LMP1) by the Ubiquitin-Proteasome Pathway , 2000, The Journal of Biological Chemistry.

[44]  Hiroshi Kawabata,et al.  Transferrin Receptor 2-α Supports Cell Growth Both in Iron-chelated Cultured Cells and in Vivo * , 2000, The Journal of Biological Chemistry.

[45]  A. Sorkin,et al.  Inhibition of the receptor‐binding function of clathrin adaptor protein AP‐2 by dominant‐negative mutant μ2 subunit and its effects on endocytosis , 1999, The EMBO journal.

[46]  D. M. Penny,et al.  The Hereditary Hemochromatosis Protein, HFE, Specifically Regulates Transferrin-mediated Iron Uptake in HeLa Cells* , 1999, The Journal of Biological Chemistry.

[47]  A. Ciechanover,et al.  A novel site for ubiquitination: the N‐terminal residue, and not internal lysines of MyoD, is essential for conjugation and degradation of the protein , 1998, The EMBO journal.

[48]  M. Mumby,et al.  Regulation of Endosome Sorting by a Specific PP2A Isoform , 1998, The Journal of cell biology.

[49]  L. Wan,et al.  PACS-1 Defines a Novel Gene Family of Cytosolic Sorting Proteins Required for trans-Golgi Network Localization , 1998, Cell.

[50]  R. A. Warren,et al.  Distinct Saturable Pathways for the Endocytosis of Different Tyrosine Motifs* , 1998, The Journal of Biological Chemistry.

[51]  R. A. Warren,et al.  Saturation of the Endocytic Pathway for the Transferrin Receptor Does Not Affect the Endocytosis of the Epidermal Growth Factor Receptor* , 1997, The Journal of Biological Chemistry.

[52]  J. Bonifacino,et al.  Protein targeting by tyrosine- and di-leucine-based signals: evidence for distinct saturable components , 1996, The Journal of cell biology.

[53]  J. Bonifacino,et al.  Interaction of tyrosine-based sorting signals with clathrin-associated proteins. , 1995, Science.

[54]  J. J. Lucas,et al.  Elimination of the O-linked glycosylation site at Thr 104 results in the generation of a soluble human-transferrin receptor. , 1994, Blood.

[55]  C. Mikoryak,et al.  Turnover of the transferrin receptor is not influenced by removing most of the extracellular domain. , 1991, The Journal of biological chemistry.

[56]  R. Murphy,et al.  Binding to cellular receptors results in increased iron release from transferrin at mildly acidic pH. , 1991, The Journal of biological chemistry.

[57]  O. Zak,et al.  A new role for the transferrin receptor in the release of iron from transferrin. , 1991, Biochemistry.

[58]  C. Watts.  Rapid endocytosis of the transferrin receptor in the absence of bound transferrin , 1985, The Journal of cell biology.

[59]  U. K. Laemmli,et al.  Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4 , 1970, Nature.