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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 -
Small GTPases Jul 2020Mutant RAS isoforms are the most common oncogenes affecting human cancers. After decades of effort in developing drugs targeting oncogenic RAS-driven cancers, we are... (Review)
Review
Mutant RAS isoforms are the most common oncogenes affecting human cancers. After decades of effort in developing drugs targeting oncogenic RAS-driven cancers, we are still charting an unclear path. Despite recent developments exemplified by KRAS (G12C) inhibitors, direct targeting of mutant RAS remains a difficult endeavor. Inhibiting RAS function by targeting its post-translational prenylation processing has remained an important approach, especially with recent progress on the study of isoprenylcysteine carboxylmethyltransferase (ICMT), the unique enzyme for the last step of prenylation processing of RAS isoforms and other substrates. Inhibition of ICMT has shown efficacy both and in RAS-mutant cancer models. We will discuss the roles of RAS family of proteins in human cancers and the impact of post-prenylation carboxylmethylation on RAS driven tumorigenesis. In addition, we will review what is known of the molecular and cellular impact of ICMT inhibition on cancer cells that underlie its anti-proliferative and pro-apoptosis efficacy.
Topics: Animals; Humans; Methylation; Protein Prenylation; ras Proteins
PubMed: 29261009
DOI: 10.1080/21541248.2017.1415637 -
Genome Biology 2005We refined the motifs for carboxy-terminal protein prenylation by analysis of known substrates for farnesyltransferase (FT), geranylgeranyltransferase I (GGT1) and...
We refined the motifs for carboxy-terminal protein prenylation by analysis of known substrates for farnesyltransferase (FT), geranylgeranyltransferase I (GGT1) and geranylgeranyltransferase II (GGT2). In addition to the CaaX box for the first two enzymes, we identify a preceding linker region that appears constrained in physicochemical properties, requiring small or flexible, preferably hydrophilic, amino acids. Predictors were constructed on the basis of sequence and physical property profiles, including interpositional correlations, and are available as the Prenylation Prediction Suite (PrePS, http://mendel.imp.univie.ac.at/sat/PrePS) which also allows evaluation of evolutionary motif conservation. PrePS can predict partially overlapping substrate specificities, which is of medical importance in the case of understanding cellular action of FT inhibitors as anticancer and anti-parasite agents.
Topics: Alkyl and Aryl Transferases; Amino Acid Motifs; Amino Acid Sequence; Animals; Computational Biology; Conserved Sequence; Evolution, Molecular; Humans; Internet; Models, Molecular; Molecular Sequence Data; Protein Prenylation; Reproducibility of Results; Sequence Alignment; Software; Substrate Specificity
PubMed: 15960807
DOI: 10.1186/gb-2005-6-6-r55 -
Current Topics in Medicinal Chemistry 2003Protein prenylation involves the post-translational modification of specific protein-derived cysteine residues with farnesyl or geranylgeranyl groups through thioether... (Review)
Review
Protein prenylation involves the post-translational modification of specific protein-derived cysteine residues with farnesyl or geranylgeranyl groups through thioether linkages. Because a large number of proteins that participate in signal transduction processes require this modification, there has been intense interest in developing inhibitors of these enzymes and in clarifying the biological function of prenylation. Isoprenoid analogues have proven to be versatile tools for probing the mechanism and structure of prenyltransferases. Mechanistic probes have been created to investigate the stereochemical course and substituent effects in prenyltransferase catalyzed reactions. They have also been used to measure kinetic isotope effects and search for possible cationic intermediates. Photoaffinity labeling analogues containing either diazotrifluoropropionate or benzophenone units have been used to identify the location of isoprenoid binding sites in these enzymes. Biophysical probes incorporating fluorescent moieties or isotopic labels have been used to measure isoprenoid dissociation constants or prenyl group conformation when bound to the enzyme. Analogues containing noncognate alkene isomers or bulky substituents have also contributed to an understanding of isoprenoid recognition. Most recently, photoactive and isomeric isoprenylated analogues are providing insights into the function of protein prenylation.
Topics: Benzophenones; Binding Sites; Dimethylallyltranstransferase; Forecasting; Models, Chemical; Photoaffinity Labels; Polyisoprenyl Phosphates; Protein Binding; Protein Prenylation; Protein Processing, Post-Translational; Signal Transduction
PubMed: 12769708
DOI: 10.2174/1568026033452087 -
Biochimica Et Biophysica Acta Dec 2000There are now numerous examples of post-translational modification with geranylgeranyl or farnesyl substituents. Once thought of as solely a mechanism for association of... (Review)
Review
There are now numerous examples of post-translational modification with geranylgeranyl or farnesyl substituents. Once thought of as solely a mechanism for association of proteins with membranes, other functional aspects of protein prenylation have come to be appreciated. Although, in almost all instances, such proteins are membrane associated, they are often found to also engage in protein-protein interactions. In some instances, such interactions are critical aspects of prenylated protein trafficking. In this review, the role of prenylation in mediating protein-protein interactions will be considered. The hypothesis will be developed that such interactions occur through recognition of the prenyl group and a second domain, on the prenylated protein, by a heterodimeric protein partner.
Topics: Animals; Binding Sites; Humans; Lipid Bilayers; Polyisoprenyl Phosphates; Protein Prenylation; Protein Transport; Proteins; Subcellular Fractions
PubMed: 11111089
DOI: 10.1016/s1388-1981(00)00149-9 -
International Journal of Molecular... Apr 2023Protein prenylation is an important protein modification that is responsible for diverse physiological activities in eukaryotic cells. This modification is generally...
Protein prenylation is an important protein modification that is responsible for diverse physiological activities in eukaryotic cells. This modification is generally catalyzed by three types of prenyl transferases, which include farnesyl transferase (FT), geranylgeranyl transferase (GGT-1) and Rab geranylgeranyl transferase (GGT-2). Studies in malaria parasites showed that these parasites contain prenylated proteins, which are proposed to play multiple functions in parasites. However, the prenyl transferases have not been functionally characterized in parasites of subphylum Apicomplexa. Here, we functionally dissected functions of three of the prenyl transferases in the Apicomplexa model organism () using a plant auxin-inducible degron system. The homologous genes of the beta subunit of FT, GGT-1 and GGT-2 were endogenously tagged with AID at the C-terminus in the TIR1 parental line using a CRISPR-Cas9 approach. Upon depletion of these prenyl transferases, GGT-1 and GGT-2 had a strong defect on parasite replication. Fluorescent assay using diverse protein markers showed that the protein markers ROP5 and GRA7 were diffused in the parasites depleted with GGT-1 and GGT-2, while the mitochondrion was strongly affected in parasites depleted with GGT-1. Importantly, depletion of GGT-2 caused the stronger defect to the sorting of rhoptry protein and the parasite morphology. Furthermore, parasite motility was observed to be affected in parasites depleted with GGT-2. Taken together, this study functionally characterized the prenyl transferases, which contributed to an overall understanding of protein prenylation in and potentially in other related parasites.
Topics: Animals; Transferases; Parasites; Toxoplasma; Farnesyltranstransferase; Protein Prenylation; Protein Transport; Protozoan Proteins
PubMed: 37108334
DOI: 10.3390/ijms24087172 -
Small GTPases Mar 2018Rab GTPases, the highly conserved members of Ras GTPase superfamily are central players in the vesicular trafficking. They are critically involved in intracellular... (Review)
Review
Rab GTPases, the highly conserved members of Ras GTPase superfamily are central players in the vesicular trafficking. They are critically involved in intracellular trafficking pathway, beginning from formation of vesicles on donor membranes, defining trafficking specificity to facilitating vesicle docking on target membranes. Given the dynamic roles of Rabs during different stages of vesicular trafficking, mechanisms for their spatial and temporal regulation are crucial for normal cellular function. Regulation of Rab GTPase activity, localization and function has always been focused in and around the association of GDP dissociation inhibitor (GDI), Guanine nucleotide Exchange Factor (GEFs) and GTPase accelerating protein (GAP) to Rabs. However, several recent studies have highlighted the importance of different post-translational modifications in regulation of Rab activation and function. This review provides a summary of various post translational modifications (PTMs) and their significance to regulate localization and function of different Rabs.
Topics: Adenosine Monophosphate; Humans; Phosphorylation; Protein Prenylation; Protein Processing, Post-Translational; rab GTP-Binding Proteins
PubMed: 28426288
DOI: 10.1080/21541248.2017.1299270 -
Cell Metabolism Apr 2019Recent research focusing on brown adipose tissue (BAT) function emphasizes its importance in systemic metabolic homeostasis. We show here that genetic and...
Recent research focusing on brown adipose tissue (BAT) function emphasizes its importance in systemic metabolic homeostasis. We show here that genetic and pharmacological inhibition of the mevalonate pathway leads to reduced human and mouse brown adipocyte function in vitro and impaired adipose tissue browning in vivo. A retrospective analysis of a large patient cohort suggests an inverse correlation between statin use and active BAT in humans, while we show in a prospective clinical trial that fluvastatin reduces thermogenic gene expression in human BAT. We identify geranylgeranyl pyrophosphate as the key mevalonate pathway intermediate driving adipocyte browning in vitro and in vivo, whose effects are mediated by geranylgeranyltransferases (GGTases), enzymes catalyzing geranylgeranylation of small GTP-binding proteins, thereby regulating YAP1/TAZ signaling through F-actin modulation. Conversely, adipocyte-specific ablation of GGTase I leads to impaired adipocyte browning, reduced energy expenditure, and glucose intolerance under obesogenic conditions, highlighting the importance of this pathway in modulating brown adipocyte functionality and systemic metabolism.
Topics: Adipocytes, Brown; Adolescent; Adult; Animals; Cell Differentiation; Cell Proliferation; Cells, Cultured; Humans; Male; Mevalonic Acid; Mice; Mice, Inbred Strains; Middle Aged; Protein Prenylation; Uncoupling Protein 1; Young Adult
PubMed: 30581121
DOI: 10.1016/j.cmet.2018.11.017 -
ACS Synthetic Biology Jan 2023Reversible membrane targeting of proteins is one of the key regulators of cellular interaction networks, for example, for signaling and polarization. So-called "membrane...
Reversible membrane targeting of proteins is one of the key regulators of cellular interaction networks, for example, for signaling and polarization. So-called "membrane switches" are thus highly attractive targets for the design of minimal cells but have so far been tricky to reconstitute in vitro. Here, we introduce cell-free prenylated protein synthesis (CFpPS), which enables the synthesis and membrane targeting of proteins in a single reaction mix including the prenylation machinery. CFpPS can confer membrane affinity to any protein via addition of a 4-peptide motif to its C-terminus and offers robust production of prenylated proteins not only in their soluble forms but also in the direct vicinity of biomimetic membranes. Thus, CFpPS enabled us to reconstitute the prenylated polarity hub Cdc42 and its regulatory protein in vitro, implementing a key membrane switch. We propose CFpPS to be a versatile and effective platform for engineering complex features, such as polarity induction, in synthetic cells.
Topics: Protein Prenylation; Peptides; Transcription Factors
PubMed: 36445320
DOI: 10.1021/acssynbio.2c00406 -
British Journal of Pharmacology Mar 2003(1) Ajoene is a garlic compound with anti-platelet properties and, in addition, was shown to inhibit cholesterol biosynthesis by affecting 3-hydroxy-3-methyl-glutaryl...
(1) Ajoene is a garlic compound with anti-platelet properties and, in addition, was shown to inhibit cholesterol biosynthesis by affecting 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase and late enzymatic steps of the mevalonate (MVA) pathway. (2) MVA constitutes the precursor not only of cholesterol, but also of a number of non-sterol isoprenoids, such as farnesyl and geranylgeranyl groups. Covalent attachment of these MVA-derived isoprenoid groups (prenylation) is a required function of several proteins that regulate cell proliferation. We investigated the effect of ajoene on rat aortic smooth muscle cell proliferation as related to protein prenylation. (3) Cell counting, DNA synthesis, and cell cycle analysis showed that ajoene (1-50 micro M) interfered with the progression of the G1 phase of the cell cycle, and inhibited rat SMC proliferation. (4) Similar to the HMG-CoA reductase inhibitor simvastatin, ajoene inhibited cholesterol biosynthesis. However, in contrast to simvastatin, the antiproliferative effect of ajoene was not prevented by the addition of MVA, farnesol (FOH), and geranylgeraniol (GGOH). Labelling of smooth muscle cell cellular proteins with [3H]-FOH and [3H]-GGOH was significantly inhibited by ajoene. (5) In vitro assays for protein farnesyltransferase (PFTase) and protein geranylgeranyltransferase type I (PGGTase-I) confirmed that ajoene inhibits protein prenylation. High performance liquid chromatography (HPLC) and mass spectrometry analyses also demonstrated that ajoene causes a covalent modification of the cysteine SH group of a peptide substrate for protein PGGTase-I. (6) Altogether, our results provide evidence that ajoene interferes with the protein prenylation reaction, an effect that may contribute to its inhibition of SMC proliferation.
Topics: Animals; Aorta; Cell Division; Cells, Cultured; Disulfides; Dose-Response Relationship, Drug; Garlic; Growth Inhibitors; Male; Muscle, Smooth, Vascular; Plant Extracts; Protein Prenylation; Rats; Rats, Sprague-Dawley; Sulfoxides
PubMed: 12642382
DOI: 10.1038/sj.bjp.0705126