CAROLINE ENNS

Summary

Affiliation: Oregon Health and Science University
Country: USA

Publications

  1. pmc N-linked glycosylation is required for transferrin-induced stabilization of transferrin receptor 2, but not for transferrin binding or trafficking to the cell surface
    Ningning Zhao
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239, United States
    Biochemistry 52:3310-9. 2013
  2. pmc Increased iron loading induces Bmp6 expression in the non-parenchymal cells of the liver independent of the BMP-signaling pathway
    Caroline A Enns
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, OR, USA
    PLoS ONE 8:e60534. 2013
  3. ncbi request reprint Pumping iron: the strange partnership of the hemochromatosis protein, a class I MHC homolog, with the transferrin receptor
    C A Enns
    Department of Cell and Developmental Biology, L 215, Oregon Health Sciences University, Portland, OR 97201, USA
    Traffic 2:167-74. 2001
  4. pmc Stoichiometries of transferrin receptors 1 and 2 in human liver
    Maja Chloupkova
    Department of Cell and Developmental Biology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Mail Code L215, Portland, OR 97239, USA
    Blood Cells Mol Dis 44:28-33. 2010
  5. pmc Interaction of the hereditary hemochromatosis protein HFE with transferrin receptor 2 is required for transferrin-induced hepcidin expression
    Junwei Gao
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, OR 97239, USA
    Cell Metab 9:217-27. 2009
  6. pmc Hepatocyte-targeted HFE and TFR2 control hepcidin expression in mice
    Junwei Gao
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, OR, USA
    Blood 115:3374-81. 2010
  7. pmc The hereditary hemochromatosis protein, HFE, inhibits iron uptake via down-regulation of Zip14 in HepG2 cells
    Junwei Gao
    Department of Cell and Developmental Biology, Oregon Health and Science University, 3181 Sam Jackson Park Road, Portland, OR 97239, USA
    J Biol Chem 283:21462-8. 2008
  8. pmc Transferrin receptor 2: evidence for ligand-induced stabilization and redirection to a recycling pathway
    Martha B Johnson
    Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, OR 97239, USA
    Mol Biol Cell 18:743-54. 2007
  9. pmc Transferrin-directed internalization and cycling of transferrin receptor 2
    Juxing Chen
    Department of Cell and Developmental Biology L215, Oregon Health and Science University, Portland, OR 97239, USA
    Traffic 10:1488-501. 2009
  10. pmc Evidence for the interaction of the hereditary haemochromatosis protein, HFE, with the transferrin receptor in endocytic compartments
    Paige S Davies
    Department of Cell and Developmental Biology, L215, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239 3098, USA
    Biochem J 373:145-53. 2003

Research Grants

  1. STRUCTURE AND FUNCTION OF THE TRANSFERRIN RECEPTOR
    CAROLINE ENNS; Fiscal Year: 2002
  2. FUNCTION OF THE HEMOCHROMATOSIS PROTEIN
    CAROLINE ENNS; Fiscal Year: 2009

Collaborators

Detail Information

Publications34

  1. pmc N-linked glycosylation is required for transferrin-induced stabilization of transferrin receptor 2, but not for transferrin binding or trafficking to the cell surface
    Ningning Zhao
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239, United States
    Biochemistry 52:3310-9. 2013
    ....
  2. pmc Increased iron loading induces Bmp6 expression in the non-parenchymal cells of the liver independent of the BMP-signaling pathway
    Caroline A Enns
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, OR, USA
    PLoS ONE 8:e60534. 2013
    ..These observations suggest an important role of the non-parenchymal liver cells in regulating iron-homeostasis by acting as a source of Bmp6...
  3. ncbi request reprint Pumping iron: the strange partnership of the hemochromatosis protein, a class I MHC homolog, with the transferrin receptor
    C A Enns
    Department of Cell and Developmental Biology, L 215, Oregon Health Sciences University, Portland, OR 97201, USA
    Traffic 2:167-74. 2001
    ..The mechanism whereby a class I MHC homolog modifies the function of a membrane receptor and how this dynamic complex of molecules regulates iron transport across intestinal epithelial cells is the subject of this review...
  4. pmc Stoichiometries of transferrin receptors 1 and 2 in human liver
    Maja Chloupkova
    Department of Cell and Developmental Biology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Mail Code L215, Portland, OR 97239, USA
    Blood Cells Mol Dis 44:28-33. 2010
    ..HFE is thus present in substoichiometric concentrations with respect to both TfR1 and TfR2 in human liver tissue. This finding supports a model, in which availability of HFE is limiting for formation of complexes with TfR1 or TfR2...
  5. pmc Interaction of the hereditary hemochromatosis protein HFE with transferrin receptor 2 is required for transferrin-induced hepcidin expression
    Junwei Gao
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, OR 97239, USA
    Cell Metab 9:217-27. 2009
    ..Since the HFE alpha3 domain interacts with TfR2, these results supported our finding that TfR2/HFE complex is required for transcriptional regulation of hepcidin by holo-Tf...
  6. pmc Hepatocyte-targeted HFE and TFR2 control hepcidin expression in mice
    Junwei Gao
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, OR, USA
    Blood 115:3374-81. 2010
    ..In addition, these studies show that the use of recombinant AAV vector to deliver genes is a promising approach for studying physiologic consequences of protein complexes...
  7. pmc The hereditary hemochromatosis protein, HFE, inhibits iron uptake via down-regulation of Zip14 in HepG2 cells
    Junwei Gao
    Department of Cell and Developmental Biology, Oregon Health and Science University, 3181 Sam Jackson Park Road, Portland, OR 97239, USA
    J Biol Chem 283:21462-8. 2008
    ..Further analysis of protein turnover indicated that the half-life of Zip14 is lower in cells that express HFE. These results suggest that HFE decreases the stability of Zip14 and therefore reduces the iron loading in HepG2 cells...
  8. pmc Transferrin receptor 2: evidence for ligand-induced stabilization and redirection to a recycling pathway
    Martha B Johnson
    Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, OR 97239, USA
    Mol Biol Cell 18:743-54. 2007
    ..The mutation Y23A in the cytoplasmic domain of TfR2 inhibits its internalization and degradation, implicating YQRV as an endocytic motif...
  9. pmc Transferrin-directed internalization and cycling of transferrin receptor 2
    Juxing Chen
    Department of Cell and Developmental Biology L215, Oregon Health and Science University, Portland, OR 97239, USA
    Traffic 10:1488-501. 2009
    ..No ubiquitination of TfR2 by HA-ubiquitin was detected, indicating a lack of direct TfR2 ubiquitination involvement in its degradation...
  10. pmc Evidence for the interaction of the hereditary haemochromatosis protein, HFE, with the transferrin receptor in endocytic compartments
    Paige S Davies
    Department of Cell and Developmental Biology, L215, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239 3098, USA
    Biochem J 373:145-53. 2003
    ..Analysis of endosomal pH and the iron content of internalized Tf indicated that HFE does not appear to alter the unloading of iron from Tf in the endosome...
  11. ncbi request reprint The hereditary hemochromatosis protein, HFE, lowers intracellular iron levels independently of transferrin receptor 1 in TRVb cells
    Hanqian Carlson
    Department of Cell and Developmental Biology L215, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA
    Blood 105:2564-70. 2005
    ....
  12. ncbi request reprint Expression of epithelial cell iron-related genes upon infection by Neisseria meningitidis
    Robert A Bonnah
    Vaccine and Gene Therapy Institute, Oregon Health and Sciences University, Portland, OR, USA
    Cell Microbiol 6:473-84. 2004
    ..This finding suggests that low IRP activity may be responsible in part for the decrease in TfR-1 mRNA levels. A discussion of these novel findings in relation to MC infection and virulence is provided...
  13. ncbi request reprint Localization of iron metabolism-related mRNAs in rat liver indicate that HFE is expressed predominantly in hepatocytes
    An Sheng Zhang
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, OR 97239, USA
    Blood 103:1509-14. 2004
    ..Western blot analysis confirmed this finding. Unexpectedly, HSCs also had high levels of DMT1 and ferroportin, implicating them in either iron sensing or iron cycling...
  14. pmc Hemojuvelin-neogenin interaction is required for bone morphogenic protein-4-induced hepcidin expression
    An Sheng Zhang
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239, USA
    J Biol Chem 284:22580-9. 2009
    ..Combined with our previous studies, our results support that hepatic neogenin possesses two functions, mediation of cellular HJV release, and stimulation of HJV-enhanced hepcidin expression...
  15. pmc The role of hepatocyte hemojuvelin in the regulation of bone morphogenic protein-6 and hepcidin expression in vivo
    An Sheng Zhang
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239, USA
    J Biol Chem 285:16416-23. 2010
    ....
  16. pmc Processing of hemojuvelin requires retrograde trafficking to the Golgi in HepG2 cells
    Julia E Maxson
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, OR 97239, USA
    Blood 113:1786-93. 2009
    ..Neogenin does not, however, play a role in HJV trafficking to the cell surface, suggesting that it could be involved either in retrograde trafficking of HJV or in cleavage leading to HJV release...
  17. pmc Suppression of hepatic hepcidin expression in response to acute iron deprivation is associated with an increase of matriptase-2 protein
    An Sheng Zhang
    Department of Cell and Developmental Biology, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
    Blood 117:1687-99. 2011
    ..However, an increase in matriptase-2 protein in the liver from ID rats was detected, suggesting that suppression of hepcidin expression in response to acute iron deprivation is mediated by an increase in matriptase-2 protein levels...
  18. pmc Neogenin-mediated hemojuvelin shedding occurs after hemojuvelin traffics to the plasma membrane
    An Sheng Zhang
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239, USA
    J Biol Chem 283:17494-502. 2008
    ....
  19. ncbi request reprint Evidence that inhibition of hemojuvelin shedding in response to iron is mediated through neogenin
    An Sheng Zhang
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239, USA
    J Biol Chem 282:12547-56. 2007
    ..The finding that neither BMP4 nor its antagonist, noggin, was able to alter HJV shedding support the lack of involvement of BMP signaling pathway in this process...
  20. pmc Mechanisms of HFE-induced regulation of iron homeostasis: Insights from the W81A HFE mutation
    An Sheng Zhang
    Department of Cell Biology L215, Oregon Health and Science University, Portland, OR 97239, USA
    Proc Natl Acad Sci U S A 100:9500-5. 2003
    ..The results indicate that HFE can lower intracellular iron levels independently of its interaction with the TfR...
  21. ncbi request reprint Lipooligosaccharide-independent alteration of cellular homeostasis in Neisseria meningitidis-infected epithelial cells
    Robert A Bonnah
    Vaccine and Gene Therapy Institute, Portland, OR, USA
    Cell Microbiol 7:869-85. 2005
    ..However, TNFalpha induction and changes in iron homeostasis observed in MC-infected epithelial cells are independent of LOS...
  22. ncbi request reprint Interaction of hemojuvelin with neogenin results in iron accumulation in human embryonic kidney 293 cells
    An Sheng Zhang
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239, USA
    J Biol Chem 280:33885-94. 2005
    ....
  23. ncbi request reprint Possible roles of the hereditary hemochromatosis protein, HFE, in regulating cellular iron homeostasis
    Caroline A Enns
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, OR 97239, USA
    Biol Res 39:105-11. 2006
    ..This review gives the background and a model as to possible mechanisms of how HFE could exert different effects on iron homeostasis in different cell types...
  24. ncbi request reprint The Cytoplasmic domain of transferrin receptor 2 dictates its stability and response to holo-transferrin in Hep3B cells
    Juxing Chen
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239, USA
    J Biol Chem 282:6201-9. 2007
    ..These results suggest that although holo-Tf binding to the ectodomain is necessary, the cytoplasmic domain of TfR2 is largely responsible for its stabilization by holo-Tf...
  25. ncbi request reprint Heterotypic interactions between transferrin receptor and transferrin receptor 2
    Todd M Vogt
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland OR 97201 3098, USA
    Blood 101:2008-14. 2003
    ..TfR and TfR2 have similar cellular localizations in K562 cells and coimmunoprecipitate to only a very limited extent. Western analysis of the receptors under nonreducing conditions reveals that they can form heterodimers...
  26. ncbi request reprint Increased IRP1 and IRP2 RNA binding activity accompanies a reduction of the labile iron pool in HFE-expressing cells
    Cindy N Roy
    Department of Cell and Developmental Biology, Oregon Health Sciences University, Portland, Oregon 97201 3098, USA
    J Cell Physiol 190:218-26. 2002
    ..These results all point to the direct effect of the interaction of HFE with transferrin receptor in lowering the intracellular labile iron pool and establishing a new set point for iron regulation within the cell...
  27. ncbi request reprint Expression of the hereditary hemochromatosis protein HFE increases ferritin levels by inhibiting iron export in HT29 cells
    Paige S Davies
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239 3098, USA
    J Biol Chem 279:25085-92. 2004
    ..Such a distinction suggests a multifunctional role for HFE that is dependent upon expression levels of proteins involved in iron transport...
  28. pmc Iron homeostasis: recently identified proteins provide insight into novel control mechanisms
    An Sheng Zhang
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239, USA
    J Biol Chem 284:711-5. 2009
    ..Disruption of these processes causes either iron-deficient anemia or iron overload disorders. In this minireview, we focus on the roles of recently identified proteins in the regulation of iron homeostasis...
  29. ncbi request reprint HFE modulates transferrin receptor 2 levels in hepatoma cells via interactions that differ from transferrin receptor 1-HFE interactions
    Juxing Chen
    Department of Cell and Developmental Biology, Oregon Health and Science University, Portland, Oregon 97239, USA
    J Biol Chem 282:36862-70. 2007
    ..Furthermore, we found that HFE increases TfR2 levels in hepatic cells independent of holo-Tf...
  30. ncbi request reprint Diferric transferrin regulates transferrin receptor 2 protein stability
    Martha B Johnson
    Department of Biochemistry, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA
    Blood 104:4287-93. 2004
    ..Our results support a role for TfR2 in monitoring iron levels by sensing changes in the concentration of diferric Tf...
  31. ncbi request reprint Association of human transferrin receptor with GABARAP
    Frank Green
    Department of Cell and Developmental Biology, L215, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97201 3098, USA
    FEBS Lett 518:101-6. 2002
    ..Our results show that GABARAP plays a more general role outside the confines of neuronal cells and GABA(A) receptors...
  32. pmc Hepatic macrophage iron aggravates experimental alcoholic steatohepatitis
    Shigang Xiong
    Department of Pathology, Keck School of Medicine, University of Southern California, 1333 San Pablo St, MMR 402, Los Angeles, CA 90033 9141, USA
    Am J Physiol Gastrointest Liver Physiol 295:G512-21. 2008
    ..Our results suggest enhanced iron uptake as a mechanism of KC iron loading in ALD and demonstrate the ILI response as a function acquired by differentiated macrophages in humans and as a priming mechanism for ALD...
  33. ncbi request reprint The molecular mechanism for receptor-stimulated iron release from the plasma iron transport protein transferrin
    Anthony M Giannetti
    Division of Biology 114 96, California Institute of Technology, Pasadena, California 91125, USA
    Structure 13:1613-23. 2005
    ....

Research Grants2

  1. STRUCTURE AND FUNCTION OF THE TRANSFERRIN RECEPTOR
    CAROLINE ENNS; Fiscal Year: 2002
    ..Understanding this process will give insight into such diseases as hemochromatosis, hyperlipidemia, and virally-mediated down regulation of immune responses. ..
  2. FUNCTION OF THE HEMOCHROMATOSIS PROTEIN
    CAROLINE ENNS; Fiscal Year: 2009
    ..The long term goal of this work is to understand the function of HFE. ..