Armin Spök

Dr. Armin Spök

orcid

Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 1998 in Molecular Biology of the Cell
Verified
Journal Article
Closed access
RLRegina Leber
Regina Leber
KLKarina Landl
Karina Landl
EZErwin Zinser
Erwin Zinser
HAHorst Ahorn
Horst Ahorn
ASArmin Spök
Armin Spök
GDGünther Daum
Günther Daum
Squalene epoxidase, encoded by the ERG1 gene in yeast, is a key enzyme of sterol biosynthesis. Analysis of subcellular fractions revealed that squalene epoxidase was present in the microsomal fraction (30,000 × g) and also cofractionated with lipid particles. A dual localization of Erg1p was confirmed by immunofluorescence microscopy. On the basis of the distribution of marker proteins, 62% of cellular Erg1p could be assigned to the endoplasmic reticulum and 38% to lipid particles in late logarithmic-phase cells. In contrast, sterol Δ24-methyltransferase (Erg6p), an enzyme catalyzing a late step in sterol biosynthesis, was found mainly in lipid particles cofractionating with triacylglycerols and steryl esters. The relative distribution of Erg1p between the endoplasmic reticulum and lipid particles changes during growth. Squalene epoxidase (Erg1p) was absent in an erg1 disruptant strain and was induced fivefold in lipid particles and in the endoplasmic reticulum when theERG1 gene was overexpressed from a multicopy plasmid. The amount of squalene epoxidase in both compartments was also induced approximately fivefold by treatment of yeast cells with terbinafine, an inhibitor of the fungal squalene epoxidase. In contrast to the distribution of the protein, enzymatic activity of squalene epoxidase was only detectable in the endoplasmic reticulum but was absent from isolated lipid particles. When lipid particles of the wild-type strain and microsomes of an erg1 disruptant were mixed, squalene epoxidase activity was partially restored. These findings suggest that factor(s) present in the endoplasmic reticulum are required for squalene epoxidase activity. Close contact between lipid particles and endoplasmic reticulum may be necessary for a concerted action of these two compartments in sterol biosynthesis.

15 May 2017 in Environmental Evidence
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Journal Article
Open access
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NHNeal Haddaway
Neal Haddaway
CKC. Kohl
C. Kohl
NSN. Rebelo da Silva
N. Rebelo da Silva
JSJ. Schiemann
J. Schiemann
ASArmin Spök
Armin Spök
RWRalf Wilhelm
Ralf Wilhelm
People have a stake in conservation and environmental management both for their own interests and the sake of the environment itself. Environmental decision-making has changed somewhat in recent decades to account for unintentional impacts on human wellbeing. The involvement of stakeholders in environmental projects has been recognised as critical for ensuring their success and equally for the syntheses of evidence of what works, where, and for whom, providing key benefits and challenges. As a result of increased interest in systematic reviews of complex management issues, there is a need for guidance in best practices for stakeholder engagement. Here, we propose a framework for stakeholder engagement in systematic reviews/systematic maps, highlighting recommendations and advice that are critical for effective, efficient and meaningful engagement of stakeholders. The discussion herein aims to provide a toolbox of stakeholder engagement activities, whilst also recommending approaches from stakeholder engagement research that may prove to be particularly useful for systematic reviews and systematic maps.

1 September 2008 in Trends in Biotechnology
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Journal Article
Closed access
ASArmin Spök
Armin Spök
RTRichard Twyman
Richard Twyman
RFRainer Fischer
Rainer Fischer
JMJulian K.C. Ma
Julian K.C. Ma
PSPenelope A.C. Sparrow
Penelope A.C. Sparrow

31 August 2022 in Frontiers in Genome Editing
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Journal Article
Open access
ASArmin Spök
Armin Spök
TSThorben Sprink
Thorben Sprink
AAAndrew C. Allan
Andrew C. Allan
TYTomiko Yamaguchi
Tomiko Yamaguchi
CDChristian Dayé
Christian Dayé
The agricultural biotechnology world has been divided into two blocks; countries adopting GM crops for commercial cultivation (adopters) and others without any or without relevant cultivation of such crops (non-adopters). Meanwhile, an increasing number of adopter countries have exempted certain genome-edited (GE) crops from legal GMO pre-market approval and labelling requirements. Among them are major exporters of agricultural commodities such as United States, Canada, and Australia. Due to the relaxed legislation more GE plants are expected to enter the market soon. Many countries in the non-adopter group, however, depend on import of large volumes of agricultural commodities from adopter countries. Unlike first generation GM, certain GE crops cannot be identified as unambiguously originating from genome editing using available techniques. Consequently, pressure is mounting on non-adopter jurisdictions to reconsider their policies and legislations. Against this backdrop, the paper explores recent developments relevant for social acceptability in selected non-adopters, Japan, New Zealand, the EU, Norway, and Switzerland in contrast to United States, Canada, and Australia. While Japan is already opening-up and Norway and Switzerland are discussing revisions of their policies, the EU and New Zealand are struggling with challenges resulting from high court decisions. In an attempt to take a closer look into the inner dynamics of these developments, the concept of social acceptability proposed by Wüstenhagen et al. (Energy Policy, 2007, 35(5), 2683–2691) is employed. This aids the understanding of developments in the jurisdictions considered and identifies specific or cross-cutting challenges.

2 October 2014 in Archives of Toxicology
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Journal Article
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DZDagmar Zeljenková
Dagmar Zeljenková
KAKatarína Ambrušová
Katarína Ambrušová
MBMária Bartušová
Mária Bartušová
AKAnton Kebis
Anton Kebis
JKJevgenij Kovrižnych
Jevgenij Kovrižnych
PSPablo Steinberg
Pablo Steinberg
The GMO Risk Assessment and Communication of Evidence (GRACE; www.grace-fp7.eu) project is funded by the European Commission within the 7th Framework Programme. A key objective of GRACE is to conduct 90-day animal feeding trials, animal studies with an extended time frame as well as analytical, in vitro and in silico studies on genetically modified (GM) maize in order to comparatively evaluate their use in GM plant risk assessment. In the present study, the results of two 90-day feeding trials with two different GM maize MON810 varieties, their near-isogenic non-GM varieties and four additional conventional maize varieties are presented. The feeding trials were performed by taking into account the guidance for such studies published by the EFSA Scientific Committee in 2011 and the OECD Test Guideline 408. The results obtained show that the MON810 maize at a level of up to 33 % in the diet did not induce adverse effects in male and female Wistar Han RCC rats after subchronic exposure, independently of the two different genetic backgrounds of the event.

12 February 2019 in Archives of Toxicology
Verified
Journal Article
Open access
PDF file
PSPablo Steinberg
Pablo Steinberg
HVHilko van der Voet
Hilko van der Voet
PGPaul W. Goedhart
Paul W. Goedhart
Gijs A. Kleter KleterGijs A. Kleter Kleter
Gijs A. Kleter Kleter
EKEsther J. Kok
Esther J. Kok
RWRalf Wilhelm
Ralf Wilhelm
In 2012, a controversial study on the long-term toxicity of a Roundup herbicide and the glyphosate-tolerant genetically modified (GM) maize NK603 was published. The EC-funded G-TwYST research consortium tested the potential subchronic and chronic toxicity as well as the carcinogenicity of the glyphosate-resistant genetically modified maize NK603 by performing two 90-day feeding trials, one with GM maize inclusion rates of 11 and 33% and one with inclusion rates of up to 50%, as well as a 2-year feeding trial with inclusion rates of 11 and 33% in male and female Wistar Han RCC rats by taking into account OECD Guidelines for the testing of chemicals and EFSA recommendations on the safety testing of whole-food/feed in laboratory animals. In all three trials, the NK603 maize, untreated and treated once with Roundup during its cultivation, and the conventional counterpart were tested. Differences between each test group and the control group were evaluated. Equivalence was assessed by comparing the observed difference to differences between non-GM reference groups in previous studies. In case of significant differences, whether the effects were dose-related and/or accompanied by changes in related parameters including histopathological findings was evaluated. It is concluded that no adverse effects related to the feeding of the NK603 maize cultivated with or without Roundup for up to 2 years were observed. Based on the outcome of the subchronic and combined chronic toxicity/carcinogenicity studies, recommendations on the scientific justification and added value of long-term feeding trials in the GM plant risk assessment process are presented.