UZH-Logo

Maintenance Infos

Regulated Function of the Prolyl-4-Hydroxylase Domain (PHD) Oxygen Sensor Proteins


Nytko, K J; Spielmann, P; Camenisch, G; Wenger, R H; Stiehl, D P (2007). Regulated Function of the Prolyl-4-Hydroxylase Domain (PHD) Oxygen Sensor Proteins. Antioxidants & Redox Signaling, 9(9):1329-1338.

Abstract

ABSTRACT Cellular oxygen is sensed by prolyl-4-hydroxylase domain (PHD) proteins that hydroxylate hypoxia-inducible factor (HIF) α subunits. Under normoxic conditions, hydroxylated HIFα is bound by the von Hippel-Lindau (pVHL) tumor suppressor, leading to ubiquitinylation and proteasomal degradation. Under hypoxic conditions hydroxylation becomes reduced, leading to HIFα stabilization. We recently showed that changes in PHD abundance and activity can regulate HIFα stability under normoxic as well as under hypoxic conditions. Thus, the PHD oxygen sensors themselves represent effectors of cellular signalling pathways as well as potential drug targets. Here, we applied a cell-free in vitro microtiter plate-based peptide hydroxylation assay to investigate the influence of ferrous iron, Krebs cycle intermediates, transition metals, vitamin C and other antioxidants on the activity of purified PHD1 to 3. PHD activity depends not only on oxygen availability but is also regulated by iron, vitamin C and Krebs cycle intermediates, suggesting a physiological relevance of their cellular concentrations. Copper but not iron, cobalt or nickel salts catalyzed vitamin C oxidation. While vitamin C is essential for PHD activity in vitro, N-acetyl-L-cysteine had no effect, and gallic acid or n-propyl gallate efficiently inhibited the activity of all three PHDs, demonstrating different functions of these antioxidants.

Abstract

ABSTRACT Cellular oxygen is sensed by prolyl-4-hydroxylase domain (PHD) proteins that hydroxylate hypoxia-inducible factor (HIF) α subunits. Under normoxic conditions, hydroxylated HIFα is bound by the von Hippel-Lindau (pVHL) tumor suppressor, leading to ubiquitinylation and proteasomal degradation. Under hypoxic conditions hydroxylation becomes reduced, leading to HIFα stabilization. We recently showed that changes in PHD abundance and activity can regulate HIFα stability under normoxic as well as under hypoxic conditions. Thus, the PHD oxygen sensors themselves represent effectors of cellular signalling pathways as well as potential drug targets. Here, we applied a cell-free in vitro microtiter plate-based peptide hydroxylation assay to investigate the influence of ferrous iron, Krebs cycle intermediates, transition metals, vitamin C and other antioxidants on the activity of purified PHD1 to 3. PHD activity depends not only on oxygen availability but is also regulated by iron, vitamin C and Krebs cycle intermediates, suggesting a physiological relevance of their cellular concentrations. Copper but not iron, cobalt or nickel salts catalyzed vitamin C oxidation. While vitamin C is essential for PHD activity in vitro, N-acetyl-L-cysteine had no effect, and gallic acid or n-propyl gallate efficiently inhibited the activity of all three PHDs, demonstrating different functions of these antioxidants.

Citations

17 citations in Web of Science®
19 citations in Scopus®
Google Scholar™

Altmetrics

Additional indexing

Item Type:Journal Article, refereed
Communities & Collections:04 Faculty of Medicine > Institute of Physiology
07 Faculty of Science > Institute of Physiology
Dewey Decimal Classification:570 Life sciences; biology
Uncontrolled Keywords:PHD, Prolyl-4-Hydroxylase ascorbate, HIF, hypoxia, oxygen sensing
Language:English
Date:2007
Deposited On:11 Feb 2008 12:21
Last Modified:05 Apr 2016 12:18
Publisher:Mary Ann Liebert
ISSN:1523-0864
Funders:Forschungskredit of the University of Zürich, Olga Mayenfisch-Stiftung, Sassella-Stifung, Krebsliga des Kantons Zürich, 6th Framework Programme of the European Commission/SBF (EUROXY LSHC-CT-2003-502932/SBF Nr. 03.0647-2), Swiss National Science Fou
Publisher DOI:https://doi.org/10.1089/ars.2007.1683
Related URLs:http://www.liebertpub.com/publication.aspx?pub_id=4

Download

Full text not available from this repository.
View at publisher

TrendTerms

TrendTerms displays relevant terms of the abstract of this publication and related documents on a map. The terms and their relations were extracted from ZORA using word statistics. Their timelines are taken from ZORA as well. The bubble size of a term is proportional to the number of documents where the term occurs. Red, orange, yellow and green colors are used for terms that occur in the current document; red indicates high interlinkedness of a term with other terms, orange, yellow and green decreasing interlinkedness. Blue is used for terms that have a relation with the terms in this document, but occur in other documents.
You can navigate and zoom the map. Mouse-hovering a term displays its timeline, clicking it yields the associated documents.

Author Collaborations