β-Trcp mediates ubiquitination and degradation of the erythropoietin receptor and controls cell proliferation

Blood ◽  
2007 ◽  
Vol 109 (12) ◽  
pp. 5215-5222 ◽  
Author(s):  
Laure Meyer ◽  
Bénédicte Deau ◽  
Hana Forejtníková ◽  
Dominique Duménil ◽  
Florence Margottin-Goguet ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Cell Proliferation ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Ubiquitin Proteasome System ◽  
Erythropoietin Receptor ◽  
Serine Residue ◽  
Cell Production ◽  
Ubiquitin Proteasome ◽  
Binding Sequence

Abstract Control of intensity and duration of erythropoietin (Epo) signaling is necessary to tightly regulate red blood cell production. We have recently shown that the ubiquitin/proteasome system plays a major role in the control of Epo-R signaling. Indeed, after Epo stimulation, Epo-R is ubiquitinated and its intracellular part is degraded by the proteasome, preventing further signal transduction. The remaining part of the receptor and associated Epo are internalized and degraded by the lysosomes. We show that β-Trcp is responsible for Epo-R ubiquitination and degradation. After Epo stimulation, β-Trcp binds to the Epo-R. This binding, like Epo-R ubiquitination, requires Jak2 activation. The Epo-R contains a typical DSG binding sequence for β-Trcp that is highly conserved among species. Interestingly, this sequence is located in a region of the Epo-R that is deleted in patients with familial polycythemia. Mutation of the serine residue of this motif to alanine (Epo-RS462A) abolished β-Trcp binding, Epo-R ubiquitination, and degradation. Epo-RS462A activation was prolonged and BaF3 cells expressing this receptor are hypersensitive to Epo, suggesting that part of the hypersensitivity to Epo in familial polycythemia could be the result of the lack of β-Trcp recruitment to the Epo-R.

scholarly journals Erythropoietin in Brain Development and Beyond

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Mawadda Alnaeeli ◽  
Li Wang ◽  
Barbora Piknova ◽  
Heather Rogers ◽  
Xiaoxia Li ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Types ◽  
Erythropoietin Receptor ◽  
Adult Brain ◽  
Receptor Expression ◽  
Neural Cells ◽  
Erythroid Progenitor ◽  
Cell Production ◽  
Oxygen Carrying Capacity

Erythropoietin is known as the requisite cytokine for red blood cell production. Its receptor, expressed at a high level on erythroid progenitor/precursor cells, is also found on endothelial, neural, and other cell types. Erythropoietin and erythropoietin receptor expression in the developing and adult brain suggest their possible involvement in neurodevelopment and neuroprotection. During ischemic stress, erythropoietin, which is hypoxia inducible, can contribute to brain homeostasis by increasing red blood cell production to increase the blood oxygen carrying capacity, stimulate nitric oxide production to modulate blood flow and contribute to the neurovascular response, or act directly on neural cells to provide neuroprotection as demonstrated in culture and animal models. Clinical studies of erythropoietin treatment in stroke and other diseases provide insight on safety and potential adverse effects and underscore the potential pleiotropic activity of erythropoietin. Herein, we summarize the roles of EPO and its receptor in the developing and adult brain during health and disease, providing first a brief overview of the well-established EPO biology and signaling, its hypoxic regulation, and role in erythropoiesis.

scholarly journals Rational engineering of an erythropoietin fusion protein to treat hypoxia

2021 ◽  
Author(s):  
Jungmin Lee ◽  
Andyna Vernet ◽  
Nathalie G. Gruber ◽  
Kasia M. Kready ◽  
Devin R. Burrill ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Blood Cell ◽  
Fusion Protein ◽  
Red Blood Cell ◽  
Receptor Activation ◽  
Erythropoietin Receptor ◽  
Neuroprotective Activity ◽  
Erythroid Cell ◽  
Glycophorin A

Erythropoietin enhances oxygen delivery and reduces hypoxia-induced cell death, but its pro-thrombotic activity is problematic for use of erythropoietin in treating hypoxia. We constructed a fusion protein that stimulates red blood cell production and neuroprotection without triggering platelet production, a marker for thrombosis. The protein consists of an anti-glycophorin A nanobody and an erythropoietin mutant (L108A). The mutation reduces activation of erythropoietin receptor homodimers that induce erythropoiesis and thrombosis, but maintains the tissue-protective signaling. The binding of the nanobody element to glycophorin A rescues homodimeric erythropoietin receptor activation on red blood cell precursors. In a cell proliferation assay, the fusion protein is active at 10-14M, allowing an estimate of the number of receptor-ligand complexes needed for signaling. This fusion protein stimulates erythroid cell proliferation in vitro and in mice, and shows neuroprotective activity in vitro. Our erythropoietin fusion protein presents a novel molecule for treating hypoxia.

SCFβ-TRCP Mediates Ubiquitination and Degradation of the Erythropoietin Receptor and Controls Cell Proliferation.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 464-464
Author(s):  
Frederique Verdier ◽  
Laure Meyer ◽  
Benedicte Deau ◽  
Hana Forejtnikova ◽  
Dominique Dumenil ◽  
...  
Keyword(s):  
Binding Site ◽  
Ubiquitin Ligase ◽  
Blood Cells ◽  
E3 Ubiquitin Ligase ◽  
Ubiquitin Proteasome System ◽  
Erythropoietin Receptor ◽  
Erythroid Progenitors ◽  
Ubiquitin Proteasome ◽  
Binding Sequence ◽  
Stimulation Of

Abstract Control of intensity and duration of erythropoietin (Epo) signalling is necessary to tightly regulate red blood cells production. After Epo stimulation of erythroid cells, 2 types of signal are transduced via the Epo receptor (Epo-R): positive signals involved in survival and proliferation, and negative signals involved in signal arrest. We have recently shown that the ubiquitin/ proteasome system plays a major role in the control of Epo-R signalling duration and desensitisation processes. Indeed, after Epo stimulation the Epo-R is ubiquitinated and its intracellular part is degraded by the proteasome, preventing further signal transduction. The remaining part of the receptor, together with associated Epo is internalised and degraded by the lysosomes (Walrafen et al 2005 Blood, 105, 600-608). Our aim was to identify the E3 ubiquitin ligase involved in Epo-R ubiquitination. The Epo-R contains a putative β-Trcp binding site in its intracellular domain. Interestingly, this putative binding sequence is located in a region of the Epo-R that is deleted in erythroid progenitors from patients with familial polycythemia. We show that β-Trcp is responsible for Epo-R ubiquitination upon Epo stimulation. After Epo stimulation, β-Trcp binds to the Epo-R and this binding is dependent on Jak2 activation. Mutation of the Ser 462 residue of the Epo-R, located in the consensus β-Trcp binding site abolished β-Trcp binding, Epo-R ubiquitination and EpoR cleavage by the proteasome. Activation of the mutated Epo-R is prolonged in comparaison with Epo-R WT and BaF3 cells expressing this mutated receptor unable to bind β-Trcp are hypersensitive to Epo. Whether the removal of the β-Trcp binding site contributes to the hypersensitivity to Epo in familial polycythemia is currently under study.]

scholarly journals Targeted Application of Human Genetic Variation Can Improve Red Blood Cell Production from Stem Cells

2016 ◽  
Vol 18 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Felix C. Giani ◽  
Claudia Fiorini ◽  
Aoi Wakabayashi ◽  
Leif S. Ludwig ◽  
Rany M. Salem ◽  
...  
Keyword(s):  
Stem Cells ◽  
Genetic Variation ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Human Genetic Variation ◽  
Cell Production

Gfi1 ubiquitination and proteasomal degradation is inhibited by the ubiquitin ligase Triad1

Blood ◽  
2007 ◽  
Vol 110 (9) ◽  
pp. 3128-3135 ◽  
Author(s):  
Jurgen A. F. Marteijn ◽  
Laurens T. van der Meer ◽  
Liesbeth van Emst ◽  
Simon van Reijmersdal ◽  
Willemijn Wissink ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Ubiquitin Ligase ◽  
Ubiquitin Proteasome System ◽  
Proteasomal Degradation ◽  
Binding Domain ◽  
U937 Cells ◽  
Dna Binding Domain ◽  
Protein Levels ◽  
Ubiquitin Ligase Activity ◽  
Ubiquitin Proteasome

Abstract Growth factor independence 1 (Gfi1) is a transcriptional repressor essential for the function and development of many different hematopoietic lineages. The Gfi1 protein expression is regulated by the ubiquitin-proteasome system. In granulocytes, Gfi1 is rapidly degraded by the proteasome, while it is more stable in monocytes. How the ubiquitination and degradation of Gfi1 is regulated is unclear. Here, we show that the ubiquitin ligase Triad1 interacts with the DNA-binding domain of Gfi1. Unexpectedly, we found that Triad1 inhibited Gfi1 ubiquitination, resulting in a prolonged half-life. Down-regulation of endogenous Triad1 by siRNAs resulted in increased Gfi1 ubiquitination. In U937 cells, Triad1 caused an increase in endogenous Gfi1 protein levels and slowed cell proliferation in a similar manner when Gfi1 itself was expressed. A Triad1 mutant that lacks the Gfi1-binding domain did not affect Gfi1 levels and proliferation. Because neither proteasome-ubiquitin nor Triad1 ubiquitin ligase activity was required for the inhibition of Gfi1 ubiquitination, these data suggest that Triad1 competes for Gfi1 binding with as yet to be identified E3 ubiquitin ligases that do mark Gfi1 for proteasomal degradation. The finetuning of Gfi1 protein levels regulated by Triad1 defines an unexpected role for this protein in hematopoiesis.

Lipocalin 2 functions as a negative regulator of red blood cell production in an autocrine fashion

2005 ◽  
Vol 19 (13) ◽  
pp. 1881-1883 ◽  
Author(s):  
Ken‐Ichi Miharada ◽  
Takashi Hiroyama ◽  
Kazuhiro Sudo ◽  
Toshiro Nagasawa ◽  
Yukio Nakamura
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Negative Regulator ◽  
Lipocalin 2 ◽  
Cell Production

Role for BH3-Only Protein NOXA In Growth-Factor Deprivation and Early Erythropoiesis

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4235-4235
Author(s):  
Christian R. Geest ◽  
Felix M. Wensveen ◽  
Sten F.W.M. Libregts ◽  
Alex M. de Bruin ◽  
Ingrid A.M. Derks ◽  
...  
Keyword(s):  
Growth Factor ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Erythroid Cell ◽  
Erythroid Progenitors ◽  
Erythroid Progenitor ◽  
Apoptosis Pathway ◽  
Cell Production ◽  
Growth Factor Deprivation ◽  
Redundant Role

Abstract Abstract 4235 Red blood cell production is a strictly regulated process and homeostatic maintenance of the erythropoietic system requires equilibrium between the rate of erythroid cell production and red blood cell destruction. Hematopoietic cytokines play a crucial role in regulating expansion, differentiation and survival of erythrocyte progenitors. Shortage of growth factors triggers the mitochondrial apoptosis pathway, which is critically dependent on Bcl-2 family members. However, the contribution of this mechanism in the regulation of erythropoiesis remains ill-defined. This prompted us to screen for candidate genes involved in this process in erythroid progenitors. We found that the expression of Noxa, a pro-apoptotic Bcl-2 family member, is upregulated during erythroid differentiation and following cytokine-withdrawal in erythroid progenitor cells. Knockdown or deletion of Noxa in IL-3 dependent human and murine erythroid progenitor cell lines increased Mcl-1 levels, which correlated with markedly decreased apoptosis following cytokine withdrawal. Importantly, Noxa ablation in mice increased extra-medullary erythropoiesis, resulting in enhanced numbers of early splenic erythroblasts and circulating reticulocytes. Noxa-deficient hematopoietic progenitors were more resistant to apoptosis induced by growth factor deprivation and displayed increased colony-forming potential. In addition, combined loss of Noxa and Bim resulted in enhanced resistance of erythroid progenitors to cytokine withdrawal compared to WT or single Bim knockouts, suggesting a non-redundant role for Noxa and Bim in regulating survival of erythroid progenitors in response to cytokine deprivation. Finally, in a model of acute haemolytic anaemia, deletion of Noxa enhanced subsequent hematocrit recovery. Together, these findings identify a non-redundant role for BH3-only protein Noxa in the regulation of erythroblast survival during early erythropoiesis. Therefore, Noxa may be a novel component to control red blood cell numbers and modulation of this pathway could be envisaged in therapeutic options for treatment of anaemia. Disclosures: No relevant conflicts of interest to declare.

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