scholarly journals Galactose oxidase/kelch repeat-containing protein is involved in the iron deficiency stress response in the roots of Hyoscyamus albus

Plant Root ◽  
2017 ◽  
Vol 11 (0) ◽  
pp. 58-63
Author(s):  
Yuki Kawahara ◽  
Takashi Hashimoto ◽  
Hideki Nakayama ◽  
Yoshie Kitamura
Keyword(s):  
Stress Response ◽  
Iron Deficiency ◽  
Galactose Oxidase ◽  
Hyoscyamus Albus

Iron deficiency stress response ofTolmiea Menziesii1

1991 ◽  
Vol 14 (11) ◽  
pp. 1145-1150 ◽  
Author(s):  
David R. Hershey
Keyword(s):  
Stress Response ◽  
Iron Deficiency

scholarly journals Derepression of the Bacillus subtilis PerR Peroxide Stress Response Leads to Iron Deficiency

2011 ◽  
Vol 194 (5) ◽  
pp. 1226-1235 ◽  
Author(s):  
M. J. Faulkner ◽  
Z. Ma ◽  
M. Fuangthong ◽  
J. D. Helmann
Keyword(s):  
Bacillus Subtilis ◽  
Stress Response ◽  
Iron Deficiency ◽  
Peroxide Stress

scholarly journals HRI coordinates translation by eIF2αP and mTORC1 to mitigate ineffective erythropoiesis in mice during iron deficiency

Blood ◽  
2018 ◽  
Vol 131 (4) ◽  
pp. 450-461 ◽  
Author(s):  
Shuping Zhang ◽  
Alejandra Macias-Garcia ◽  
Jason Velazquez ◽  
Elena Paltrinieri ◽  
Randal J. Kaufman ◽  
...  
Keyword(s):  
Stress Response ◽  
Iron Deficiency ◽  
Hypochromic Anemia ◽  
Integrated Stress Response ◽  
Ineffective Erythropoiesis ◽  
Key Points ◽  
Mtorc1 Signaling

Key Points Erythroid eIF2αP and ATF4 are essential for iron-restricted erythropoiesis, and HRI-eIF2αP is responsible for microcytic hypochromic anemia. HRI activates integrated stress response and represses mTORC1 signaling in ID to mitigate ineffective erythropoiesis.

Heme-Regulated eIF2α Kinase in Erythropoiesis and Oxidative Stress

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. SCI-23-SCI-23
Author(s):  
Jane-Jane Chen
Keyword(s):  
Oxidative Stress ◽  
Protein Synthesis ◽  
Stress Response ◽  
Iron Deficiency ◽  
Erythroid Differentiation ◽  
Α Subunit ◽  
Translational Initiation ◽  
Eif2α Phosphorylation ◽  
Iron Heme ◽  
And Oxidative Stress

Abstract SCI-23 Besides serving as a prosthetic group for hemoglobin, heme also regulates translation by inhibiting the kinase activity of heme-regulated translational inhibitor (HRI). HRI is the only known protein kinase that senses the intracellular heme concentration and does so through its two heme-binding domains. HRI is activated in heme deficiency by autophosphorylation, and phosphorylates the α-subunit of eukaryotic initiation factor 2 (eIF2α), which impairs the recycling of eIF2 for further translational initiation and results in cessation of protein synthesis. In this manner, HRI serves as a feedback inhibitor and coordinates the translation of globin mRNAs with the intracellular heme concentration to ensure that globin proteins are not made in excess of the heme available for the formation of hemoglobin. Excess of globin chains or heme is cytotoxic. In the absence of HRI, uncontrolled protein synthesis in heme deficiency results in globin aggregation and precipitation in red blood cells and their precursors. HRI is responsible for the physiological adaptation that produces hypochromic, microcytic erythrocytes in iron deficiency. The expression of HRI was increased during late stages of erythropoiesis with higher expression in Ter119high erythroblasts and reticulocytes, correlating with the active synthesis and regulation of globins at these stages of erythroid differentiation. In addition to inhibiting global protein synthesis, the second important function of eIF2α phosphorylation is to reprogram translation and the subsequent transcription of genes required for stress response. In mammalian cells, translation of the transcription factor ATF4 mRNA is upregulated specifically by eIF2α phosphorylation via upstream open reading frames in the 5’UTR. Activation of the HRI-ATF4 stress response pathway in nucleated erythroid precursors is required for adaptation to acute and chronic oxidative stress. Furthermore, this HRI-dependent ATF4 pathway is also operative and necessary for erythroid differentiation, especially under stress conditions. In chronic iron deficiency, HRI is necessary for adaptive gene expression for erythroid differentiation as well as for iron heme and redox homeostasis. Beyond heme deficiency and oxidative stress, HRI is also activated by osmotic shock and heat shock. HRI deficiency in mice exacerbates erythropoietic protoporphyria and renders β-thalassemia intermedia embryonically lethal. Hri−/− mice also develop ineffective erythropoiesis during iron/heme deficiency and are severely compromised upon phenylhydrazine-induced acute hemolytic anemia. Thus, translational regulation by HRI plays a critical role in the manifestation of red cell diseases in mice and may be a significant modifier of such diseases in humans. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Root tip-dependent, active riboflavin secretion by Hyoscyamus albus hairy roots under iron deficiency

2008 ◽  
Vol 46 (4) ◽  
pp. 452-460 ◽  
Author(s):  
Ataru Higa ◽  
Erika Miyamoto ◽  
Laiq ur Rahman ◽  
Yoshie Kitamura
Keyword(s):  
Iron Deficiency ◽  
Hairy Roots ◽  
Root Tip ◽  
Hyoscyamus Albus
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