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Small GTPase
Small GTPases (), also known as small G-proteins, are a family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate (GTP). They are a type of G-protein found in the cytosol that are homologous to the alpha subunit of heterotrimeric G-proteins, but unlike the alpha subunit of G proteins, a small GTPase can function independently as a hydrolase enzyme to bind to and hydrolyze a guanosine triphosphate (GTP) to form guanosine diphosphate (GDP). The best-known members are the Ras GTPases and hence they are sometimes called Ras subfamily GTPases. A typical G-protein is active when bound to GTP and inactive when bound to GDP (i.e. when the GTP is hydrolyzed to GDP). The GDP can then be replaced by free GTP. Therefore, a G-protein can be switched on and off. GTP hydrolysis is accelerated by GTPase activating proteins (GAPs), while GTP exchange is catalyzed by guanine nucleotide exchange factors (GEFs). Activation of a GEF typically activates its cognate G-protein, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolase
In biochemistry, hydrolases constitute a class of enzymes that commonly function as biochemical catalysts that use water to break a chemical bond: :\ce \quad \xrightarrowtext\quad \ce This typically results in dividing a larger molecule into smaller molecules. Some common examples of hydrolase enzymes are esterases including lipases, phosphatases, glycosidases, peptidases, and nucleosidases. Esterases cleave ester bonds in lipids and phosphatases cleave phosphate groups off molecules. An example of crucial esterase is acetylcholine esterase, which assists in transforming the neuron impulse into the acetate group after the hydrolase breaks the acetylcholine into choline and acetic acid. Acetic acid is an important metabolite in the body and a critical intermediate for other reactions such as glycolysis. Lipases hydrolyze glycerides. Glycosidases cleave sugar molecules off carbohydrates and peptidases hydrolyze peptide bonds. Nucleosidases hydrolyze the bonds of nucleo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipid
Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries, and in nanotechnology. Lipids are broadly defined as hydrophobic or amphiphilic small molecules; the amphiphilic nature of some lipids allows them to form structures such as vesicles, multilamellar/ unilamellar liposomes, or membranes in an aqueous environment. Biological lipids originate entirely or in part from two distinct types of biochemical subunits or "building-blocks": ketoacyl and isoprene groups. Using this approach, lipids may be divided into eight categories: fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from condensatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IQGAP
IQ motif containing GTPase activating protein (IQGAP) is a carrier protein. It is associated with the Rho GTP-binding protein. Genes * IQGAP1 Ras GTPase-activating-like protein IQGAP1 (IQGAP1) also known as p195 is a ubiquitously expressed protein that in humans is encoded by the ''IQGAP1'' gene. IQGAP1 is a scaffold protein involved in regulating various cellular processes ranging fro ..., IQGAP2, IQGAP3 See also * IQ calmodulin-binding motif References GTP-binding protein regulators {{protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RRAD (gene)
Ras Related Glycolysis Inhibitor and Calcium Channel Regulator (RRAD) is a protein that in humans is encoded by the ''RRAD'' gene. RRAD is a Ras-related small GTPase that is regulated by p53 and plays a role in the regulation of aerobic glycolysis. Interactions RRAD has been shown to interact with CAMK2G and TPM2 β-Tropomyosin, also known as tropomyosin beta chain is a protein that in humans is encoded by the ''TPM2'' gene. β-tropomyosin is striated muscle-specific coiled coil dimer that functions to stabilize actin filaments and regulate muscle contra .... References Further reading * * * * * * * * * * * * * * * External links * {{gene-16-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rap GTP-binding Protein
Rap GTP-binding protein also known as Ras-related proteins or simply RAP is a type of small GTPase, similar in structure to Ras. These proteins share approximately 50% amino acid identity with the classical RAS proteins and have numerous structural features in common. The most striking difference between RAP proteins and RAS proteins resides in their 61st amino acid: glutamine in RAS is replaced by threonine in RAP proteins. RAP counteracts the mitogenic function of RAS because it can interact with RAS GAPs and RAF in a competitive manner. Family members Human genes that encode Ras-related proteins include: * RAP1A, RAP1B * RAP2A Ras-related protein Rap-2a is a protein that in humans is encoded by the ''RAP2A'' gene. RAP2A is a member of the Ras-related protein family. Interactions RAP2A has been shown to interact with RUNDC3A, RASSF5 Ras association domain-cont ..., RAP2B, RAP2C * RAB5C References External links * EC 3.6.5 Peripheral membrane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rit2
GTP-binding protein Rit2 is a protein that in humans is encoded by the ''RIT2'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei .... RIN belongs to the RAS (HRAS; MIM 190020) superfamily of small GTPases (Shao et al., 1999). upplied by OMIMref name="entrez"/> RIT2 has been associated with Parkinson's disease in two large genetic studies. An gene expression study of postmortem brain has suggested RIT2 interacts with interferon-γ signalling. Interactions RIT2 has been shown to interact with POU4F1. References Further reading * * * * * * {{gene-18-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ral-B
Ras-related protein Ral-B (RalB) is a protein that in humans is encoded by the ''RALB'' gene on chromosome 2. This protein is one of two paralogs of the Ral protein, the other being RalA, and part of the Ras GTPase family. RalA functions as a molecular switch to activate a number of biological processes, majorly cell division and transport, via signaling pathways. Its biological role thus implicates it in many cancers. Structure The Ral isoforms share an 80% overall match in amino acid sequence and 100% match in their effector-binding region. The two isoforms mainly differ in the C-terminal hypervariable region, which contains multiple sites for post-translational modification, leading to diverging subcellular localization and biological function. For example, phosphorylation of Serine 194 on RalA by the kinase Aurora A results in the relocation of RalA to the inner mitochondrial membrane, where RalA helps carry out mitochondrial fission; whereas phosphorylation of Serine 198 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ral-A
Ras-related protein Ral-A (RalA) is a protein that in humans is encoded by the ''RALA'' gene on chromosome 7. This protein is one of two paralogs of the Ral protein, the other being RalB, and part of the Ras GTPase family. RalA functions as a molecular switch to activate a number of biological processes, majorly cell division and transport, via signaling pathways. Its biological role thus implicates it in many cancers. Structure The Ral isoforms share an 80% overall match in amino acid sequence and 100% match in their effector-binding region. The two isoforms mainly differ in the C-terminal hypervariable region, which contains multiple sites for post-translational modification, leading to diverging subcellular localization and biological function. For example, phosphorylation of Serine 194 on RalA by the kinase Aurora A results in the relocation of RalA to the inner mitochondrial membrane, where RalA helps carry out mitochondrial fission; whereas phosphorylation of Serine 198 on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADP Ribosylation Factor
ADP ribosylation factors (ARFs) are members of the ARF family of GTP-binding proteins of the Ras superfamily. ARF family proteins are ubiquitous in eukaryotic cells, and six highly conserved members of the family have been identified in mammalian cells. Although ARFs are soluble, they generally associate with membranes because of N-terminus myristoylation. They function as regulators of vesicular traffic and actin remodelling. The small ADP ribosylation factor (Arf) GTP-binding proteins are major regulators of vesicle biogenesis in intracellular traffic. They are the founding members of a growing family that includes Arl (Arf-like), Arp (Arf-related proteins) and the remotely related Sar (Secretion-associated and Ras-related) proteins. Arf proteins cycle between inactive GDP-bound and active GTP-bound forms that bind selectively to effectors. The classical structural GDP/GTP switch is characterised by conformational changes at the so-called switch 1 and switch 2 regions, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rab (G-protein)
The Rab family of proteins is a member of the Ras superfamily of small G proteins. Approximately 70 types of Rabs have now been identified in humans. Rab proteins generally possess a GTPase fold, which consists of a six-stranded beta sheet which is flanked by five alpha helices. Rab GTPases regulate many steps of membrane trafficking, including vesicle formation, vesicle movement along actin and tubulin networks, and membrane fusion. These processes make up the route through which cell surface proteins are trafficked from the Golgi to the plasma membrane and are recycled. Surface protein recycling returns proteins to the surface whose function involves carrying another protein or substance inside the cell, such as the transferrin receptor, or serves as a means of regulating the number of a certain type of protein molecules on the surface. Function Rab proteins are peripheral membrane proteins, anchored to a membrane via a lipid group covalently linked to an amino acid. Spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
