Oxysterols inhibit plant Sterol methyl transferase type-1 enzyme activity in vitro

Sterols are important structural components of eukaryotic cell membranes, where they influence membrane fluidity and permeability. Sterols contain a four-ring structure with a hydrocarbon side-chain. The sterol composition and structure differs among plants, mammals and fungi. Mammals and fungi cont...

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Autor principal: Shirazi, Taraneh
Formato: H2
Lenguaje:Inglés
Publicado: SLU/Dept. of Plant Biology and Forest Genetics (until 131231) 2013
Materias:
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author Shirazi, Taraneh
author_browse Shirazi, Taraneh
author_facet Shirazi, Taraneh
author_sort Shirazi, Taraneh
collection Epsilon Archive for Student Projects
description Sterols are important structural components of eukaryotic cell membranes, where they influence membrane fluidity and permeability. Sterols contain a four-ring structure with a hydrocarbon side-chain. The sterol composition and structure differs among plants, mammals and fungi. Mammals and fungi contain a single main sterol such as cholesterol or ergosterol, respectively. In contrast, plants contain a mixture of several sterols with varying side-chain length such as sitosterol, stigmasterol and 24-methyl cholesterol. Side-chain length is regulated by the two enzymes, Sterol methyl transferase type-1 (SMT1) and type-2 (SMT2) which increase side-chain length by a methyl (SMT1) or ethyl (SMT2) group. Thus, regulation of SMT enzyme activity is crucial for sterol composition in plants. This project considers to what extent oxysterols, oxidized sterol forms, can regulate SMT1 activity. SMT1 activity was assayed in microsome preparations from three plant species, and different oxysterols were added to the enzyme reaction to investigate the effect on enzyme activity. Results showed that oxysterols inhibited SMT1 activity in all plant species tested. The inhibitory effect was stronger for side-chain oxysterols (24-OH and 25-OH cholesterol) than for ring hydroxylated ones (7β-OH cholesterol). The results suggest that oxysterols have an inhibitory effect on SMT1 activity in plants, and may be part of a feed-back regulation of sterol composition.
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institution Swedish University of Agricultural Sciences
language Inglés
publishDate 2013
publishDateSort 2013
publisher SLU/Dept. of Plant Biology and Forest Genetics (until 131231)
publisherStr SLU/Dept. of Plant Biology and Forest Genetics (until 131231)
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spelling RepoSLU56952023-11-18T02:32:04Z Oxysterols inhibit plant Sterol methyl transferase type-1 enzyme activity in vitro Shirazi, Taraneh oxysterol sterol sterol methyl transferase plant secondary metabolism Sterols are important structural components of eukaryotic cell membranes, where they influence membrane fluidity and permeability. Sterols contain a four-ring structure with a hydrocarbon side-chain. The sterol composition and structure differs among plants, mammals and fungi. Mammals and fungi contain a single main sterol such as cholesterol or ergosterol, respectively. In contrast, plants contain a mixture of several sterols with varying side-chain length such as sitosterol, stigmasterol and 24-methyl cholesterol. Side-chain length is regulated by the two enzymes, Sterol methyl transferase type-1 (SMT1) and type-2 (SMT2) which increase side-chain length by a methyl (SMT1) or ethyl (SMT2) group. Thus, regulation of SMT enzyme activity is crucial for sterol composition in plants. This project considers to what extent oxysterols, oxidized sterol forms, can regulate SMT1 activity. SMT1 activity was assayed in microsome preparations from three plant species, and different oxysterols were added to the enzyme reaction to investigate the effect on enzyme activity. Results showed that oxysterols inhibited SMT1 activity in all plant species tested. The inhibitory effect was stronger for side-chain oxysterols (24-OH and 25-OH cholesterol) than for ring hydroxylated ones (7β-OH cholesterol). The results suggest that oxysterols have an inhibitory effect on SMT1 activity in plants, and may be part of a feed-back regulation of sterol composition. SLU/Dept. of Plant Biology and Forest Genetics (until 131231) 2013 H2 eng https://stud.epsilon.slu.se/5695/
spellingShingle oxysterol
sterol
sterol methyl transferase
plant secondary metabolism
Shirazi, Taraneh
Oxysterols inhibit plant Sterol methyl transferase type-1 enzyme activity in vitro
title Oxysterols inhibit plant Sterol methyl transferase type-1 enzyme activity in vitro
title_full Oxysterols inhibit plant Sterol methyl transferase type-1 enzyme activity in vitro
title_fullStr Oxysterols inhibit plant Sterol methyl transferase type-1 enzyme activity in vitro
title_full_unstemmed Oxysterols inhibit plant Sterol methyl transferase type-1 enzyme activity in vitro
title_short Oxysterols inhibit plant Sterol methyl transferase type-1 enzyme activity in vitro
title_sort oxysterols inhibit plant sterol methyl transferase type-1 enzyme activity in vitro
topic oxysterol
sterol
sterol methyl transferase
plant secondary metabolism