Abstract
3-Hydroxy-3-methylglutaryl-CoA reductase (HMGR) is unique in the first part of the cytoplasmic isoprenoid pathway, as it contains a membrane domain that includes ER-specific retention motifs. When fused to GFP, this domain targets two tobacco BY-2 HMGR isoforms differentially. While the first isoform is ER-localized, a second stress-induced one forms globular structures connected by tubular structures. A serine positioned upstream of the ER retention motif seems to be implicated in this specific subcellular localization. Surprisingly, these structures are closely connected to F-actin, and their intactness is dependent upon the integrity of the filaments or the action of a calmodulin antagonist.
MeSH terms
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Actins / metabolism*
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Amino Acid Sequence
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Base Sequence
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Cell Line
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Cloning, Molecular
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DNA, Plant / genetics
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Endoplasmic Reticulum / enzymology
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Green Fluorescent Proteins / genetics
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Green Fluorescent Proteins / metabolism
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Hydroxymethylglutaryl CoA Reductases / chemistry
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Hydroxymethylglutaryl CoA Reductases / genetics
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Hydroxymethylglutaryl CoA Reductases / metabolism*
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Isoenzymes / chemistry
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Isoenzymes / genetics
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Isoenzymes / metabolism
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Molecular Sequence Data
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Nicotiana / enzymology*
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Nicotiana / genetics
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Plants, Genetically Modified
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Protein Structure, Tertiary
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Recombinant Fusion Proteins / chemistry
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Sequence Homology, Amino Acid
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Serine / chemistry
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Subcellular Fractions / enzymology
Substances
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Actins
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DNA, Plant
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Isoenzymes
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Recombinant Fusion Proteins
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Green Fluorescent Proteins
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Serine
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Hydroxymethylglutaryl CoA Reductases