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Biochimie Aug 2016Little is known about how plant cells regulate the exchange of prenyl diphosphates between the two compartmentalized isoprenoid biosynthesis pathways. Prenylation of...
Little is known about how plant cells regulate the exchange of prenyl diphosphates between the two compartmentalized isoprenoid biosynthesis pathways. Prenylation of proteins is a suitable model to study such interactions between the plastidial methylerythritol phosphate (MEP) and the cytosolic mevalonate (MVA) pathways because prenyl moieties used to modify proteins rely on both origins. Tobacco cells expressing a prenylatable GFP were treated with specific MEP and/or MVA pathways inhibitors to block the formation of prenyl diphosphates and therefore the possibility to modify the proteins. Chemical complementation assays using prenyl alcohol precursors restore the prenylation. Indeed, geranylgeraniol (C20 prenyl alcohol) and to a lesser but significant level C15-farnesol restored the prenylation of a protein bearing a geranylgeranylation CaaX motif, which under standard conditions is modified by a MEP-derived prenyl group. However, the restoration takes place in different ways. While geranylgeraniol operates directly as a metabolic precursor, the C15-prenyl alcohol functions indirectly as a signal that leads to shift the metabolic origin of prenyl groups in modified proteins, here from the plastidial MEP pathway in favor of the cytosolic MVA pathway. Furthermore, farnesol interferes negatively with the MEP pathway in an engineered Escherichia coli strain synthesizing isoprenoids either starting from MVA or from MEP. Following the cellular uptake of a fluorescent analog of farnesol, we showed its close interaction with tobacco plastids and modification of plastid homeostasis. As a consequence, in tobacco farnesol supposedly inhibits the plastidial MEP pathway and activates the cytosolic MVA pathway, leading to the shift in the metabolic origin and thereby acts as a potential regulator of crosstalk between the two pathways. Together, those results suggest a new role for farnesol (or a metabolite thereof) as a central molecule for the regulation of isoprenoid biosynthesis in plants.
Topics: Cell Line; Erythritol; Farnesol; Plant Proteins; Plastids; Protein Prenylation; Sugar Phosphates
PubMed: 27138105
DOI: 10.1016/j.biochi.2016.04.021 -
Current Opinion in Plant Biology Dec 2003Protein farnesylation has an important role in the regulation of plant development and signal transduction, but the exact function of this modification is not well... (Review)
Review
Protein farnesylation has an important role in the regulation of plant development and signal transduction, but the exact function of this modification is not well understood. The identification of protein farnesyltransferase substrates, together with the genetic analysis of mutants that are deficient in protein farnesylation, should significantly increase our knowledge of this form of protein modification in plants.
Topics: Mutation; Plant Development; Plant Proteins; Plants; Protein Prenylation; Signal Transduction
PubMed: 14611950
DOI: 10.1016/j.pbi.2003.09.005 -
Methods in Molecular Biology (Clifton,... 1999
Review
Topics: Animals; Diterpenes; Farnesol; Hemiterpenes; Isotope Labeling; Pentanols; Protein Prenylation
PubMed: 10399150
DOI: 10.1385/1-59259-264-3:125 -
Biochimica Et Biophysica Acta Mar 1996Isoprenylation/methylation is an important dual hydrophobic post-translational modification which occurs at or near a carboxyl terminal cysteine residue. All known G... (Review)
Review
Isoprenylation/methylation is an important dual hydrophobic post-translational modification which occurs at or near a carboxyl terminal cysteine residue. All known G proteins are modified in this way, making the pathway of central interest for an understanding of signal transduction. In this review, aspects of the molecular enzymology of isoprenylation/methylation are reviewed. The functional significance of these modifications is discussed, with special reference to the signal transducing G proteins. Of further interest is the possible regulatory role of methylation, since this step is the only reversible one in the pathway. The biochemical and functional consequences of isoprenylation/methylation are of especial interest. Isoprenylation/methylation is generally assumed to enhance the abilities of modified proteins to associate with membranes. This can be due either to hydrophobic lipid-lipid or lipid-protein interactions. Available evidence, taken largely from studies on visual signal transduction and ras signalling pathways, strongly points to enhanced membrane binding being a consequence of hydrophobic lipid-lipid interactions. An exciting possibility that also emerges is concerned with whether isoprenylation may also have additional roles, in addition to enhancing the membrane partitioning ability of the modified protein. In a simple mechanism of this type, the isoprenylated/methylated cysteine residue would be specifically recognized by another protein. While no compelling case can yet be made for an effector role for the isoprenylated/methylated cysteine moiety mediating protein-protein interactions, recent studies on the pharmacology of isoprenylated cysteine analogs suggests the possibility of such a role.
Topics: Dimethylallyltranstransferase; Endopeptidases; Methylation; Methyltransferases; Protein Prenylation; Protein Processing, Post-Translational; Structure-Activity Relationship
PubMed: 8608162
DOI: 10.1016/0005-2760(95)00233-2 -
Critical Care Medicine Nov 2003
Topics: Animals; Anti-Ulcer Agents; Diterpenes; HSP70 Heat-Shock Proteins; Protein Prenylation; Rats; ras Proteins
PubMed: 14605546
DOI: 10.1097/01.CCM.0000092457.89851.EB -
Current Opinion in Chemical Biology Dec 2012Protein post-translational modifications increase the functional diversity of the proteome by covalently adding chemical moieties onto proteins thereby changing their... (Review)
Review
Protein post-translational modifications increase the functional diversity of the proteome by covalently adding chemical moieties onto proteins thereby changing their activation state, cellular localization, interacting partners, and life cycle. Lipidation is one such modification that enables membrane association of naturally cytosolic proteins. Protein prenyltransferases irreversibly install isoprenoid units of varying length via a thioether linkage onto proteins that exert their cellular activity at membranes. Substrates of prenyltransferases are involved in countless signaling pathways and processes within the cell. Identification of new prenylation substrates, prenylation pathway regulators, and dynamic trafficking of prenylated proteins are all avenues of intense, ongoing research that are challenging, exciting, and have the potential to significantly advance the field in the near future.
Topics: Animals; Bacterial Infections; Bacterial Physiological Phenomena; Dimethylallyltranstransferase; Host-Pathogen Interactions; Humans; Neoplasms; Protein Prenylation; Substrate Specificity
PubMed: 23141597
DOI: 10.1016/j.cbpa.2012.10.015 -
Archives of Biochemistry and Biophysics Mar 1997Etiolated spinach seedlings, as well as petioles and blades of leaves of green seedlings, were labeled with [3H]mevalonate to study protein prenylation in several plant...
Etiolated spinach seedlings, as well as petioles and blades of leaves of green seedlings, were labeled with [3H]mevalonate to study protein prenylation in several plant developmental stages. The polypeptide prenylation pattern of the leaf petiole and the leaf blade differed considerably, although some prenylated proteins were present in both tissues. During greening several prenylated polypeptides in the 30- to 46-kDa molecular mass region and two at 15 kDa became more abundant, while others in the 21.5- to 30-kDa region and one at 62 kDa showed a relative decrease. However, the relative amount of several of the prenylated polypeptides did not appear to be altered during the greening process. In etiolated seedlings, more thioether-linked farnesol than geranylgeraniol was found, whereas in seedlings grown under normal light conditions the converse situation prevailed.
Topics: Chlorophyll; Chromatography, High Pressure Liquid; Gene Expression Regulation, Developmental; Light; Mevalonic Acid; Plant Proteins; Protein Prenylation; Spinacia oleracea
PubMed: 9056235
DOI: 10.1006/abbi.1996.9816 -
Expert Review of Proteomics Jun 2017Protein prenylation is a ubiquitous covalent post-translational modification characterized by the addition of farnesyl or geranylgeranyl isoprenoid groups to a cysteine... (Review)
Review
Protein prenylation is a ubiquitous covalent post-translational modification characterized by the addition of farnesyl or geranylgeranyl isoprenoid groups to a cysteine residue located near the carboxyl terminal of a protein. It is essential for the proper localization and cellular activity of numerous proteins, including Ras family GTPases and G-proteins. In addition to its roles in cellular physiology, the prenylation process has important implications in human diseases and in the recent years, it has become attractive target of inhibitors with therapeutic potential. Areas covered: This review attempts to summarize the basic aspects of prenylation integrating them with biological functions in diseases and giving an account of the current status of prenylation inhibitors as potential therapeutics. We also summarize the methodologies for the characterization of this modification. Expert commentary: The growing body of evidence suggesting an important role of prenylation in diseases and the subsequent development of inhibitors of the enzymes responsible for this modification lead to the urgent need to identify the full spectrum of prenylated proteins that are altered in the disease or affected by drugs. Proteomic tools to analyze prenylated proteins are recently emerging, thanks to the advancement in the field of mass spectrometry coupled to enrichment strategies.
Topics: Cysteine; Humans; Protein Prenylation; Protein Processing, Post-Translational; Proteins; Proteomics
PubMed: 28521569
DOI: 10.1080/14789450.2017.1332998 -
Methods in Molecular Biology (Clifton,... 2013Lipid modifications play a key role in protein targeting and function. The two Arabidopsis Gγ subunits, AGG1 and AGG2, have been shown to undergo prenylation (AGG1) and...
Lipid modifications play a key role in protein targeting and function. The two Arabidopsis Gγ subunits, AGG1 and AGG2, have been shown to undergo prenylation (AGG1) and S-acylation (AGG2). Prenylation involves covalent nonreversible attachment of either farnesyl (15 carbons) or geranylgeranyl (20 carbons) isoprenoids to conserved cysteine residues at or near the C-terminus of proteins. S-acylation, frequently referred to as palmitoylation, involves the attachment of acyl fatty acids to thiol groups of cysteine residues through a reversible thioester bond. The procedures described below allow direct analysis of the prenyl and acyl moieties using gas chromatography-coupled mass spectrometry (GC-MS). These methods are based on (1) cleavage of prenyl groups with the Raney nickel catalyst and (2) analysis of protein S-acylation following cleavage of the acyl fatty acids from proteins by hydrogenation with platinum (IV) oxide. The hydrogenation under these conditions causes an acid transesterification of the acyl moieties, adding an ethyl group to the carboxyl head of the fatty acid. The addition of the ethyl group reduces the polarity of the fatty acids, allowing their efficient separation by gas chromatography.
Topics: Acylation; Arabidopsis; Arabidopsis Proteins; Fatty Acids; Gas Chromatography-Mass Spectrometry; Lipid Metabolism; Lipoylation; Protein Prenylation; Proteins
PubMed: 23913042
DOI: 10.1007/978-1-62703-532-3_13 -
Brain Research Dec 2002Apolipoprotein E (ApoE) genotype modulates the risk of Alzheimer's disease. ApoE has been shown essential for amyloid beta-peptide fibrillogenesis and deposition, a...
Apolipoprotein E (ApoE) genotype modulates the risk of Alzheimer's disease. ApoE has been shown essential for amyloid beta-peptide fibrillogenesis and deposition, a defining pathological feature of this disease. Because astrocytes and microglia represent the major source of extracellular apoE in brain, we investigated apoE secretion by glia. We determined that protein prenylation is required for apoE release from a continuous microglial cell line, primary mixed glia, and from organotypic hippocampal cultures. Using selective protein prenylation inhibitors, apoE secretion was found to require protein geranylgeranylation. This prenylation involved a protein critical to apoE secretion, not apoE proper. ApoE secretion could also be suppressed by inhibiting synthesis of mevalonate, the precursor to both types of protein prenylation, using hydroxyl-3-methylglutaryl coenzyme A reductase inhibitors (statins). Recent reports have described the beneficial effects of statins on the risk of dementia. Our finding that protein geranylgeranylation is required for apoE secretion in the brain parenchyma provides another contributing mechanism to explain the effective properties of statins against the development of dementia. In this model, statin-mediated inhibition of mevalonate synthesis, an essential reaction in forming geranylgeranyl lipid, would lower extracellular levels of parenchymal apoE. Because apoE has been found necessary for plaque development in transgenic models of Alzheimer's disease, suppressing apoE secretion by statins could reduce plaques and, in turn, improve cognitive function.
Topics: Alkyl and Aryl Transferases; Alzheimer Disease; Amyloid beta-Peptides; Animals; Animals, Newborn; Apolipoproteins E; Astrocytes; Brain; Cells, Cultured; Disease Models, Animal; Dose-Response Relationship, Drug; Farnesyltranstransferase; Hippocampus; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lovastatin; Mevalonic Acid; Mice; Mice, Transgenic; Microglia; Neuroglia; Polyisoprenyl Phosphates; Protein Prenylation
PubMed: 12468034
DOI: 10.1016/s0006-8993(02)03480-7