Erythropoietin: A model system for studying oxygen-dependent gene regulation

Bunn, HF; Gu, J; Huang, LE; Park, JW; Zhu, H

HERO ID

1857390

Reference Type

Journal Article

Subtype

Review

Year

1998

Language

English

PMID

9510530

HERO ID 1857390
Material Type Review
In Press No
Year 1998
Title Erythropoietin: A model system for studying oxygen-dependent gene regulation
Authors Bunn, HF; Gu, J; Huang, LE; Park, JW; Zhu, H
Journal Journal of Experimental Biology
Volume 201
Issue 8
Page Numbers 1197-1201
Abstract The physiological regulation of the red cell mass depends upon enhanced transcription of the erythropoietin (Epo) gene in response to hypoxia. Studies of Epo gene expression have been useful in investigating the mechanism by which cells and tissues sense hypoxia and respond with biologically appropriate alterations in gene expression. It is likely that oxygen sensing involves a heme protein in which cobalt and nickel can substitute for iron in the porphyrin ring. Indirect evidence suggests that the sensor is present in all cells and is a multi-subunit assembly containing an NAD(P)H oxidase capable of generating peroxide and reactive oxygen intermediates, which serve as signaling molecules. The up-regulation of Epo gene transcription by hypoxia is mediated by at least two known DNA-binding transcription factors, hypoxia-inducible factor 1 (HIF-1) and hepatic nuclear factor 4 (HNF-4), which bind to cognate response elements in a critical 3' enhancer approximately 50 bp in length. HIF-1 binding is induced by hypoxia as well as by cobalt. The activation of HIF-1 by hypoxia depends upon the selective protection of its alpha subunit from ubiquitin-dependent proteolysis by means of a mechanism that involves redox chemistry and perhaps phosphorylation. HNF-4 is an orphan nuclear receptor that is constitutively expressed in kidney and liver and which cooperates with HIF-1 to give maximal hypoxic induction. In hypoxic cells, p300 or a related family member forms a macromolecular assembly with HIF-1 and HNF-4, enabling transduction from the Epo 3' enhancer to the apparatus on the promoter responsible for the initiation of transcription.
Doi 10.1242/jeb.201.8.1197
Pmid 9510530
Wosid WOS:000073772900013
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword erythropoietin; hypoxia; gene regulation; oxygen sensing; HIF-1; HNF-4; p300