Protein Prenylation
A post-translational modification of proteins by the attachment of an isoprenoid to the C-terminal cysteine residue. The isoprenoids used, farnesyl diphosphate or geranylgeranyl diphosphate, are derived from the same biochemical pathway that produces cholesterol.
Prenylation
Attachment of isoprenoids (TERPENES) to other compounds, especially PROTEINS and FLAVONOIDS.
Alkyl and Aryl Transferases
Dimethylallyltranstransferase
An enzyme that, in the pathway of cholesterol biosynthesis, catalyzes the condensation of isopentenyl pyrophosphate and dimethylallylpyrophosphate to yield pyrophosphate and geranylpyrophosphate. The enzyme then catalyzes the condensation of the latter compound with another molecule of isopentenyl pyrophosphate to yield pyrophosphate and farnesylpyrophosphate. EC 2.5.1.1.
Farnesyltranstransferase
Mevalonic Acid
Farnesol
A colorless liquid extracted from oils of plants such as citronella, neroli, cyclamen, and tuberose. It is an intermediate step in the biological synthesis of cholesterol from mevalonic acid in vertebrates. It has a delicate odor and is used in perfumery. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
Transferases
Transferases are enzymes transferring a group, for example, the methyl group or a glycosyl group, from one compound (generally regarded as donor) to another compound (generally regarded as acceptor). The classification is based on the scheme "donor:acceptor group transferase". (Enzyme Nomenclature, 1992) EC 2.
Choroideremia
Lovastatin
A fungal metabolite isolated from cultures of Aspergillus terreus. The compound is a potent anticholesteremic agent. It inhibits 3-hydroxy-3-methylglutaryl coenzyme A reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES), which is the rate-limiting enzyme in cholesterol biosynthesis. It also stimulates the production of low-density lipoprotein receptors in the liver.
rab GTP-Binding Proteins
A large family of MONOMERIC GTP-BINDING PROTEINS that play a key role in cellular secretory and endocytic pathways. EC 3.6.1.-.
Diterpenes
Twenty-carbon compounds derived from MEVALONIC ACID or deoxyxylulose phosphate.
rhoB GTP-Binding Protein
Geranyltranstransferase
Claviceps
A genus of ascomycetous fungi, family Clavicipitaceae, order Hypocreales, parasitic on various grasses (POACEAE). The sclerotia contain several toxic alkaloids. Claviceps purpurea on rye causes ergotism.
Guanine Nucleotide Dissociation Inhibitors
Protein factors that inhibit the dissociation of GDP from GTP-BINDING PROTEINS.
rab1 GTP-Binding Proteins
A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in vesicle transport between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS and through early Golgi compartments. This enzyme was formerly listed as EC 3.6.1.47.
ras Proteins
Small, monomeric GTP-binding proteins encoded by ras genes (GENES, RAS). The protooncogene-derived protein, PROTO-ONCOGENE PROTEIN P21(RAS), plays a role in normal cellular growth, differentiation and development. The oncogene-derived protein (ONCOGENE PROTEIN P21(RAS)) can play a role in aberrant cellular regulation during neoplastic cell transformation (CELL TRANSFORMATION, NEOPLASTIC). This enzyme was formerly listed as EC 3.6.1.47.
GTP-Binding Proteins
Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.
Monomeric GTP-Binding Proteins
A class of monomeric, low molecular weight (20-25 kDa) GTP-binding proteins that regulate a variety of intracellular processes. The GTP bound form of the protein is active and limited by its inherent GTPase activity, which is controlled by an array of GTPase activators, GDP dissociation inhibitors, and guanine nucleotide exchange factors. This enzyme was formerly listed as EC 3.6.1.47
rab5 GTP-Binding Proteins
A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in transport from the cell membrane to early endosomes. This enzyme was formerly listed as EC 3.6.1.47.
Naphthols
Diphosphonates
Organic compounds which contain P-C-P bonds, where P stands for phosphonates or phosphonic acids. These compounds affect calcium metabolism. They inhibit ectopic calcification and slow down bone resorption and bone turnover. Technetium complexes of diphosphonates have been used successfully as bone scanning agents.
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Amino Acid Sequence
Proto-Oncogene Proteins p21(ras)
Cellular proteins encoded by the H-ras, K-ras and N-ras genes. The proteins have GTPase activity and are involved in signal transduction as monomeric GTP-binding proteins. Elevated levels of p21 c-ras have been associated with neoplasia. This enzyme was formerly listed as EC 3.6.1.47.
Hydroxymethylglutaryl-CoA Reductase Inhibitors
Protein Processing, Post-Translational
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
rho GTP-Binding Proteins
A large family of MONOMERIC GTP-BINDING PROTEINS that are involved in regulation of actin organization, gene expression and cell cycle progression. This enzyme was formerly listed as EC 3.6.1.47.
rhoA GTP-Binding Protein
Hemiterpenes
The five-carbon building blocks of TERPENES that derive from MEVALONIC ACID or deoxyxylulose phosphate.
Substrate Specificity
Sesquiterpenes
Sesquiterpenes are a class of terpenes consisting of three isoprene units, forming a 15-carbon skeleton, which can be found in various plant essential oils and are known for their diverse chemical structures and biological activities, including anti-inflammatory, antimicrobial, and cytotoxic properties.
Enzyme Inhibitors
Terpenes
A class of compounds composed of repeating 5-carbon units of HEMITERPENES.
Hepatitis Delta Virus
Cyclic Nucleotide Phosphodiesterases, Type 2
A cyclic nucleotide phosphodiesterase subfamily that is activated by the binding of CYCLIC GMP to an allosteric domain found on the enzyme. Multiple enzyme variants of this subtype can be produced due to multiple alternative mRNA splicing. The subfamily is expressed in a broad variety of tissues and may play a role in mediating cross-talk between CYCLIC GMP and CYCLIC CMP pathways. Although the type 2 enzymes are classified as 3',5'-cyclic-AMP phosphodiesterases (EC 3.1.4.17), members of this class have additional specificity for CYCLIC GMP.
Simvastatin
A derivative of LOVASTATIN and potent competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HYDROXYMETHYLGLUTARYL COA REDUCTASES), which is the rate-limiting enzyme in cholesterol biosynthesis. It may also interfere with steroid hormone production. Due to the induction of hepatic LDL RECEPTORS, it increases breakdown of LDL CHOLESTEROL.
Oncogene Protein p21(ras)
Transforming protein encoded by ras oncogenes. Point mutations in the cellular ras gene (c-ras) can also result in a mutant p21 protein that can transform mammalian cells. Oncogene protein p21(ras) has been directly implicated in human neoplasms, perhaps accounting for as much as 15-20% of all human tumors. This enzyme was formerly listed as EC 3.6.1.47.
Hydrogenation
Biocatalysis
Cell Membrane
Hydroxymethylglutaryl CoA Reductases
Enzymes that catalyze the reversible reduction of alpha-carboxyl group of 3-hydroxy-3-methylglutaryl-coenzyme A to yield MEVALONIC ACID.
Amino Acid Motifs
rap1 GTP-Binding Proteins
A genetically related subfamily of RAP GTP-BINDING PROTEINS that share homology with RAS PROTEINS. They bind to Ras effectors but do not activate them, therefore they may antagonize the effects of RAS PROTEINS. This enzyme was formerly listed as EC 3.6.1.47.
Hepatitis D
INFLAMMATION of the LIVER in humans caused by HEPATITIS DELTA VIRUS, a defective RNA virus that can only infect HEPATITIS B patients. For its viral coating, hepatitis delta virus requires the HEPATITIS B SURFACE ANTIGENS produced by these patients. Hepatitis D can occur either concomitantly with (coinfection) or subsequent to (superinfection) hepatitis B infection. Similar to hepatitis B, it is primarily transmitted by parenteral exposure, such as transfusion of contaminated blood or blood products, but can also be transmitted via sexual or intimate personal contact.
Progeria
An abnormal congenital condition, associated with defects in the LAMIN TYPE A gene, which is characterized by premature aging in children, where all the changes of cell senescence occur. It is manifested by premature greying; hair loss; hearing loss (DEAFNESS); cataracts (CATARACT); ARTHRITIS; OSTEOPOROSIS; DIABETES MELLITUS; atrophy of subcutaneous fat; skeletal hypoplasia; elevated urinary HYALURONIC ACID; and accelerated ATHEROSCLEROSIS. Many affected individuals develop malignant tumors, especially SARCOMA.
Ruthenium
Protein Methyltransferases
rho-Specific Guanine Nucleotide Dissociation Inhibitors
A subcategory of guanine nucleotide dissociation inhibitors that are specific for RHO GTP-BINDING PROTEINS.
Palmitic Acid
Guanosine Diphosphate
Molecular Structure
Sequence Homology, Amino Acid
GTP-Binding Protein gamma Subunits
Heterotrimeric GTP-binding protein subunits that tightly associate with GTP-BINDING PROTEIN BETA SUBUNITS. A dimer of beta and gamma subunits is formed when the GTP-BINDING PROTEIN ALPHA SUBUNIT dissociates from the GTP-binding protein heterotrimeric complex. The beta-gamma dimer can play an important role in signal transduction by interacting with a variety of second messengers.
Recombinant Fusion Proteins
Guanosine Triphosphate
Genes, ras
Family of retrovirus-associated DNA sequences (ras) originally isolated from Harvey (H-ras, Ha-ras, rasH) and Kirsten (K-ras, Ki-ras, rasK) murine sarcoma viruses. Ras genes are widely conserved among animal species and sequences corresponding to both H-ras and K-ras genes have been detected in human, avian, murine, and non-vertebrate genomes. The closely related N-ras gene has been detected in human neuroblastoma and sarcoma cell lines. All genes of the family have a similar exon-intron structure and each encodes a p21 protein.
Imidazoles
rac1 GTP-Binding Protein
A rac GTP-binding protein involved in regulating actin filaments at the plasma membrane. It controls the development of filopodia and lamellipodia in cells and thereby influences cellular motility and adhesion. It is also involved in activation of NADPH OXIDASE. This enzyme was formerly listed as EC 3.6.1.47.