A new fluorescence assay for measuring the activity of geranylgeranyl transferase (type I) is described. It does not require the use of either radiolabeled geranylgeranyl diphosphate or the purified recombinant Ras protein substrate with the carboxy terminal sequence of CVLL. Dansyl GCVLL and unlabeled geranylgeranyl diphosphate are used as substrates. The Km for Dansyl GCVLL and for geranylgeranyl diphosphate is 5 microM and 800 nM, respectively. At equimolar concentrations, enzymatic activity is higher when Dansyl GCVLL is used as a substrate compared to Dansyl GCVII. Dansyl GCVLS, a substrate for farnesyl transferase, is inactive in this assay. CVFL is a competitive inhibitor of geranylgeranyl transferase and exhibits a Ki of 200 nM.
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http://dx.doi.org/10.1006/abio.1995.1108 | DOI Listing |
Physiol Plant
January 2025
Institute for Plant Molecular and Cell Biology (IBMCP), CSIC-Universitat Politècnica de València, València, Spain.
Plant carotenoids are plastid-synthesized isoprenoids with roles as photoprotectants, pigments, and precursors of bioactive molecules such as the hormone abscisic acid (ABA). The first step of the carotenoid biosynthesis pathway is the production of phytoene from geranylgeranyl diphosphate (GGPP), catalyzed by phytoene synthase (PSY). GGPP produced by plastidial GGPP synthases (GGPPS) is channeled to the carotenoid pathway by direct interaction of GGPPS and PSY enzymes.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Department of Molecular and Cellular Biology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
Functionally derivatized analogs of prenyl lipids are valuable tools for the detection and analysis of prenylated proteins. Using a biotinylated analog of geranylgeranyl, we previously identified Ykt6 as a substrate for a novel protein prenyltransferase, termed geranylgeranyltransferase type III (GGTase-III). Ykt6 is an evolutionarily highly conserved SNARE protein that regulates multiple intracellular trafficking pathways, including intra-Golgi trafficking and autophagosome-lysosome fusion.
View Article and Find Full Text PDFNat Commun
January 2025
Key Laboratory of Marine Drugs Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, P R China.
Prenylation modifications of natural products play essential roles in chemical diversity and bioactivities, but imidazole modification prenyltransferases are not well investigated. Here, we discover a dimethylallyl tryptophan synthase family prenyltransferase, AuraA, that catalyzes the rare dimethylallylation on the imidazole moiety in the biosynthesis of aurantiamine. Biochemical assays validate that AuraA could accept both cyclo-(L-Val-L-His) and cyclo-(L-Val-DH-His) as substrates, while the prenylation modes are completely different, yielding C2-regular and C5-reverse products, respectively.
View Article and Find Full Text PDFSignal Transduct Target Ther
December 2024
National Key Laboratory of Immunity and Inflammation, Naval Medical University, Shanghai, 200433, China.
Metabolic reprogramming of host cells plays critical roles during viral infection. Itaconate, a metabolite produced from cis-aconitate in the tricarboxylic acid cycle (TCA) by immune responsive gene 1 (IRG1), is involved in regulating innate immune response and pathogen infection. However, its involvement in viral infection and underlying mechanisms remain incompletely understood.
View Article and Find Full Text PDFJ Cell Mol Med
December 2024
Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
Fibrosis, characterised by excessive extracellular matrix deposition, contributes to both organ failure and significant mortality worldwide. Whereas fibroblasts are activated into myofibroblasts, marked by phenotypic factors such as α-smooth muscle actin (α-SMA), periostin, fibroblast activation protein (FAP) and heat shock protein 47 (HSP47), the cellular processes of trans-differentiation for fibrosis development remain poorly understood. Herein, we hypothesised that the molecular signalling of geranylgeranyl pyrophosphate (GGPP), a crucial biochemical molecule for protein prenylation, is essential in the regulation of profibrotic mechanisms for fibroblast-to-myofibroblast activation.
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