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Guanine Nucleotide Exchange Factor
Guanine nucleotide exchange factors (GEFs) are proteins or protein domains that activate monomeric GTPases by stimulating the release of guanosine diphosphate (GDP) to allow binding of guanosine triphosphate (GTP). A variety of unrelated structural domains have been shown to exhibit guanine nucleotide exchange activity. Some GEFs can activate multiple GTPases while others are specific to a single GTPase. Function Guanine nucleotide exchange factors (GEFs) are proteins or protein domains involved in the activation of small GTPases. Small GTPases act as molecular switches in intracellular signaling pathways and have many downstream targets. The most well-known GTPases comprise the Ras superfamily and are involved in essential cell processes such as cell differentiation and proliferation, cytoskeletal organization, vesicle trafficking, and nuclear transport. GTPases are active when bound to GTP and inactive when bound to GDP, allowing their activity to be regulated by GEFs and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GTP Chemical Structure
GTP may refer to: Computing * Go Text Protocol * GPRS Tunnelling Protocol * .gtp, a common Gerber file extension for top solder paste mask files Government * Government Transformation Programme (Malaysia) * Graduate Teacher Programme, in England and Wales * Growth and Transformation Plan of the Government of Ethiopia Medicine and science * Gene therapy product * Guanosine triphosphate * Good tissue practice * Global warming potential#Other metrics to compare greenhouse gases, Global Temperature change Potential Vehicles, Transport, Motorsport * Grand Touring Prototype (other), Grand Touring Prototype; the IMSA GTP, a race car category ** 1st generation (1981–1993), see IMSA GTP *** BMW GTP *** Chevrolet Corvette GTP *** Consulier GTP *** Ford Mustang GTP *** Mazda GTP ** 2nd generation (2023–), see Le Mans Hypercar or LMDh * Grand Trunk Pacific Railway, a defunct Canadian railway * Pontiac Grand Prix GTP * Pontiac G6 GTP * Sisu GTP, a Finnish military vehicle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rho Family Of GTPases
The Rho family of GTPases is a family of small (~21 kDa) signaling G proteins, and is a subfamily of the Ras superfamily. The members of the Rho GTPase family have been shown to regulate many aspects of intracellular actin dynamics, and are found in all eukaryotic kingdoms, including yeasts and some plants. Three members of the family have been studied in detail: Cdc42, Rac1, and RhoA. All G proteins are "molecular switches", and Rho proteins play a role in organelle development, cytoskeletal dynamics, cell movement, and other common cellular functions. History Identification of the Rho family of GTPases began in the mid-1980s. The first identified Rho member was RhoA, isolated serendipitously in 1985 from a low stringency cDNA screening. Rac1 and Rac2 were identified next, in 1989 followed by Cdc42 in 1990. Eight additional mammalian Rho members were identified from biological screenings until the late 1990s, a turning point in biology where availability of complete genome sequenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EGF Receptor
The epidermal growth factor receptor (EGFR; ErbB-1; HER1 in humans) is a transmembrane protein that is a receptor for members of the epidermal growth factor family (EGF family) of extracellular protein ligands. The epidermal growth factor receptor is a member of the ErbB family of receptors, a subfamily of four closely related receptor tyrosine kinases: EGFR (ErbB-1), HER2/neu (ErbB-2), Her 3 (ErbB-3) and Her 4 (ErbB-4). In many cancer types, mutations affecting EGFR expression or activity could result in cancer. Epidermal growth factor and its receptor was discovered by Stanley Cohen of Vanderbilt University. Cohen shared the 1986 Nobel Prize in Medicine with Rita Levi-Montalcini for their discovery of growth factors. Deficient signaling of the EGFR and other receptor tyrosine kinases in humans is associated with diseases such as Alzheimer's, while over-expression is associated with the development of a wide variety of tumors. Interruption of EGFR signalling, either b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GRB2
Growth factor receptor-bound protein 2, also known as Grb2, is an adaptor protein involved in signal transduction/ cell communication. In humans, the GRB2 protein is encoded by the ''GRB2'' gene. The protein encoded by this gene binds receptors such as the epidermal growth factor receptor and contains one SH2 domain and two SH3 domains. Its two SH3 domains direct complex formation with proline-rich regions of other proteins, and its SH2 domain binds tyrosine phosphorylated sequences. This gene is similar to the ''sem-5'' gene of ''Caenorhabditis elegans'', which is involved in the signal transduction pathway. Two alternatively spliced transcript variants encoding different isoforms have been found for this gene. Function and expression Grb2 is widely expressed and is essential for multiple cellular functions. Inhibition of Grb2 function impairs developmental processes in various organisms and blocks transformation and proliferation of various cell types. It is thus n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAPK/ERK Pathway
The MAPK/ERK pathway (also known as the Ras-Raf-MEK-ERK pathway) is a chain of proteins in the cell (biology), cell that communicates a signal from a Receptor (biochemistry), receptor on the surface of the cell to the DNA in the nucleus of the cell. The signal starts when a signaling molecule binds to the receptor on the cell surface and ends when the DNA in the nucleus expresses a protein and produces some change in the cell, such as cell division. The pathway includes many proteins, such as mitogen-activated protein kinases (MAPKs), originally called extracellular signal-regulated kinases (ERKs), which communicate by adding phosphate groups to a neighboring protein (Phosphorylation, phosphorylating it), thereby acting as an "on" or "off" switch. When one of the proteins in the pathway is mutated, it can become stuck in the "on" or "off" position, a necessary step in the development of many cancers. In fact, components of the MAPK/ERK pathway were first discovered in cancer cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Son Of Sevenless
In cell signalling, ''Son of Sevenless'' (''SOS'') refers to a set of genes encoding guanine nucleotide exchange factors that act on the Ras subfamily of small GTPases. History and name The gene was so named because the Sos protein that it encoded was found to operate downstream of the ''sevenless'' gene in ''Drosophila melanogaster'' in a MAPK/ERK pathway, Ras/MAP kinase pathway. When ''sevenless'' is mutated or otherwise dysfunctional during development of the fly's ultraviolet light-sensitive compound eye, the seventh, central photoreceptor (R7) of each ommatidium fails to form. Similarly, the mammalian orthologues of Sos, SOS1 and SOS2, function downstream of many growth factor and adhesion receptors. Function Ras-GTPases act as molecular switches that bind to downstream effectors, such as the protein kinase c-Raf, and localise them to the membrane, resulting in their activation. Ras-GTPases are considered inactive when bound to guanosine diphosphate (GDP), and active when b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Transducing Adaptor Protein
Signal transducing adaptor proteins (STAPs) are proteins that are accessory to main proteins in a signal transduction pathway. Adaptor proteins contain a variety of protein-binding modules that link protein-binding partners together and facilitate the creation of larger signaling complexes. These proteins tend to lack any intrinsic enzymatic activity themselves, instead mediating specific protein–protein interactions that drive the formation of Multiprotein complex, protein complexes. Examples of adaptor proteins include MYD88, Grb2 and SHC1. Signaling components Much of the specificity of signal transduction depends on the recruitment of several signalling components such as protein kinases and G-protein GTPases into short-lived active complexes in response to an activating signal such as a growth factor binding to its receptor (biochemistry), receptor. Domains Adaptor proteins usually contain several domains within their structure (e.g., SH2 domain, Src homology 2 (SH2) and S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vesicle (biology)
In cell biology, a vesicle is a structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer. Vesicles form naturally during the processes of secretion ( exocytosis), uptake ( endocytosis), and the transport of materials within the plasma membrane. Alternatively, they may be prepared artificially, in which case they are called liposomes (not to be confused with lysosomes). If there is only one phospholipid bilayer, the vesicles are called '' unilamellar liposomes''; otherwise they are called ''multilamellar liposomes''. The membrane enclosing the vesicle is also a lamellar phase, similar to that of the plasma membrane, and intracellular vesicles can fuse with the plasma membrane to release their contents outside the cell. Vesicles can also fuse with other organelles within the cell. A vesicle released from the cell is known as an extracellular vesicle. Vesicles perform a variety of functions. Because it is separated from the cytoso ... [...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] |
ARF GTPase , Vitoria-Gasteiz, Spain
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ARF may refer to: Organizations * Advertising Research Foundation * Animal Rescue Foundation * Armenian Revolutionary Federation * ASEAN Regional Forum People * Cahit Arf (1910–1997), Turkish mathematician Science, medicine, and mathematics * Acute renal failure * Acute rheumatic fever * ADP ribosylation factor, a small GTP-binding protein * The Arf invariant in mathematics * Argon fluoride laser or ArF laser * Atomic Resonance Filter or atomic line filter * Auxin Response Factors in plants * p14arf or ARF tumor suppressor Other uses * Arf (''Nanoha''), character in ''Magical Girl Lyrical Nanoha'' * Abuse Reporting Format * Almost-Ready-to-Fly model aircraft * The Azkena Rock Festival The Azkena Rock Festival (a.k.a. ARF) is one of the most relevant Spanish rock festivals. It is celebrated in Vitoria-Gasteiz (Álava) organized by Last Tour International. ARF is notorious due to its diverse cartel of groups and for the submerse ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cdc42
Cell division control protein 42 homolog (Cdc42 or CDC42) is a protein that in humans is encoded by the ''CDC42'' gene. Cdc42 is involved in regulation of the cell cycle. It was originally identified in ''S. cerevisiae'' (yeast) as a mediator of cell division, and is now known to influence a variety of signaling events and cellular processes in a variety of organisms from yeast to mammals. Function Human Cdc42 is a small GTPase of the Rho family, which regulates signaling pathways that control diverse cellular functions including cell morphology, cell migration, endocytosis, cell polarity and cell cycle progression. Rho GTPases are central to dynamic actin cytoskeletal assembly and rearrangement that are the basis of cell-cell adhesion and migration. Activated Cdc42 activates by causing conformational changes in p21-activated kinases PAK1 and PAK2, which in turn initiate actin reorganization and regulate cell adhesion, migration, and invasion. Structure Cdc42 is a homodim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rac (GTPase)
Rac is a subfamily of the Rho family of GTPases, small (~21 kDa) signaling G proteins (more specifically a GTPase). Just as other G proteins, Rac acts as a molecular switch, remaining inactive while bound to guanosine diphosphate (GDP) and activated once guanine nucleotide exchange factors (GEFs) remove GDP, permitting guanosine triphosphate (GTP) to bind. When bound to GTP, Rac is activated. In its activated state, Rac participates in the regulation of cell movement, through its involvement in structural changes to the actin cytoskeleton. By changing the cytoskeletal dynamics within the cell, Rac-GTPases are able to facilitate the recruitment of neutrophils to the infected tissues, and to regulate degranulation of azurophil and integrin-dependent phagocytosis. Activated Rac also regulates the effector functions of the target proteins involved in downstream signaling. As an essential subunit of NOX2 (NADPH oxidase enzyme complex), Rac is required for ROS (reactive oxygen species) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
