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WASF1
Wiskott–Aldrich syndrome protein family member 1, also known as WASP-family verprolin homologous protein 1 (WAVE1), is a protein that in humans is encoded by the ''WASF1'' gene. Function The protein encoded by this gene, a member of the Wiskott–Aldrich syndrome protein (WASP) family, plays a critical role downstream of Rac, a Rho-family small GTPase, through its involvement in the WAVE regulatory complex in regulating the actin cytoskeleton required for membrane ruffling. It has been shown to associate with an actin nucleation core Arp2/3 complex while enhancing actin polymerization in vitro. Clinical significance Wiskott–Aldrich syndrome is a disease of the immune system, likely due to defects in regulation of actin cytoskeleton. Interactions WASF1 has been shown to interact with BAIAP2 and Profilin 1 Profilin-1 is a protein that in humans is encoded by the ''PFN1'' gene. Function The protein encoded by this gene is a ubiquitous actin monomer-binding protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WAVE Regulatory Complex
The WAVE regulatory complex (WRC, SCAR complex) is a five-subunit protein complex in the Wiskott-Aldrich syndrome protein (WASP) family involved in the formation of the actin cytoskeleton through interaction with the Arp2/3 complex. The holocomplex comprises WAVE1 (also known as WASF1), CYFIP1, ABI2, Nap1 and HSPC300 in its canonical form, or orthologues of these. Composition The proteins within the WRC form a CYFIP1-Nap1 heterodimer and a WAVE1-Abi2-HSPC300 heterotrimer, and following interaction with Rac1, the holocomplex has been observed in a CYFIP1-Nap1-Abi2 heterotrimer subcomplex and an active WAVE1-HSPC300 heterodimer subcomplex. Function WRC recruitment to the sites of actin nucleation events at the cell periphery is mediated by the binding of a number of ligands containing a conserved WRC interacting receptor sequence (WIRS) which binds to a conserved location shared across the surfaces of Abi2 and CYFIP1. The WRC is activated by interaction with the Rac1 (via ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BAIAP2
Brain-specific angiogenesis inhibitor 1-associated protein 2 is a protein that in humans is encoded by the ''BAIAP2'' gene. Function The protein encoded by this gene has been identified as a brain-specific angiogenesis inhibitor ( BAI1)-binding protein. This interaction at the cytoplasmic membrane is crucial to the function of this protein, which may be involved in neuronal growth-cone guidance. This protein functions as an insulin receptor tyrosine kinase substrate and suggests a role for insulin in the central nervous system. This protein has also been identified as interacting with the dentatorubral-pallidoluysian atrophy gene, which is associated with an autosomal dominant neurodegenerative disease. It also associates with a downstream effector of Rho small G proteins, which is associated with the formation of stress fibers and cytokinesis. Alternative splicing of the 3'-end of this gene results in three products of undetermined function. Interactions BAIAP2 has been s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and 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: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...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 GDP and activated once GEFs remove GDP, permitting 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) production involved in the formation of NETs (neutrophil extracellular traps, thus, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GTPase
GTPases are a large family of hydrolase enzymes that bind to the nucleotide guanosine triphosphate (GTP) and hydrolyze it to guanosine diphosphate (GDP). The GTP binding and hydrolysis takes place in the highly conserved P-loop "G domain", a protein domain common to many GTPases. Functions GTPases function as molecular switches or timers in many fundamental cellular processes. Examples of these roles include: * Signal transduction in response to activation of cell surface receptors, including transmembrane receptors such as those mediating taste, smell and vision. * Protein biosynthesis (a.k.a. translation) at the ribosome. * Regulation of cell differentiation, proliferation, division and movement. * Translocation of proteins through membranes. * Transport of vesicles within the cell, and vesicle-mediated secretion and uptake, through GTPase control of vesicle coat assembly. GTPases are active when bound to GTP and inactive when bound to GDP. In the generalized recepto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actin Nucleation Core
An actin nucleation core is a protein trimer with three actin monomers. It is called a nucleation core because it leads to the energetically favorable elongation reaction once a tetramer is formed from a trimer. Actin protein dimers and trimers are energetically unfavorable.Actin nucleators like the Arp2/3 complex of proteins from the formin family are most frequently involved in this process. Actin nucleation factors start the polymerization of actin within cells. Many distinct proteins that can mediate the de novo nucleation of filaments directly interact with actin and promote it. This gives protrusive membrane formations their initial impetus. These entities may take the form of pseudopodia, invadopodia, or non-apoptotic membrane blebs. Mechanism The unfavorable kinetics of actin oligomer production prevent spontaneous actin polymerization.Once an actin nucleus has been created, the connection of the monomers happens swiftly, with the plus end developing considerably more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arp2/3 Complex
Arp2/3 complex (Actin Related Protein 2/3 complex) is a seven-subunit protein complex that plays a major role in the regulation of the actin cytoskeleton. It is a major component of the actin cytoskeleton and is found in most actin cytoskeleton-containing eukaryotic cells. Two of its subunits, the ''A''ctin-''R''elated ''P''roteins ARP2 and ARP3, closely resemble the structure of monomeric actin and serve as nucleation sites for new actin filaments. The complex binds to the sides of existing ("mother") filaments and initiates growth of a new ("daughter") filament at a distinctive 70 degree angle from the mother. Branched actin networks are created as a result of this nucleation of new filaments. The regulation of rearrangements of the actin cytoskeleton is important for processes like cell locomotion, phagocytosis, and intracellular motility of lipid vesicles. The Arp2/3 complex was named after it was identified in 1994 by affinity chromatography from ''Acanthamoeba castellanii' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wiskott–Aldrich Syndrome
Wiskott–Aldrich syndrome (WAS) is a rare X-linked recessive disease characterized by eczema, thrombocytopenia (low platelet count), immune deficiency, and bloody diarrhea (secondary to the thrombocytopenia). It is also sometimes called the eczema-thrombocytopenia-immunodeficiency syndrome in keeping with Aldrich's original description in 1954. The WAS-related disorders of X-linked thrombocytopenia (XLT) and X-linked congenital neutropenia (XLN) may present with similar but less severe symptoms and are caused by mutations of the same gene. Signs and symptoms WAS occurs most often in males due to its X-linked recessive pattern of inheritance, affecting between 1 and 10 males per million. The first signs are usually petechiae and bruising, resulting from a low platelet count (i.e. thrombocytopenia). Spontaneous nose bleeds and bloody diarrhea are also common and eczema typically develops within the first month of life. Recurrent bacterial infections typically develop by three month ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune System Diseases
An immune disorder is a dysfunction of the immune system. These disorders can be characterized in several different ways: * By the component(s) of the immune system affected * By whether the immune system is overactive or underactive * By whether the condition is congenital or acquired According to the International Union of Immunological Societies, more than 150 primary immunodeficiency diseases (PIDs) have been characterized. However, the number of acquired immunodeficiencies exceeds the number of PIDs. It has been suggested that most people have at least one primary immunodeficiency. Due to redundancies in the immune system, though, many of these are never detected. Autoimmune diseases An autoimmune disease is a condition arising from an abnormal immune response to a normal body part. There are at least 80 types of autoimmune diseases. Nearly any body part can be involved. Common symptoms include low-grade fever and feeling tired. Often symptoms come and go. List of some au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actin
Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of over 100 μM; its mass is roughly 42 kDa, with a diameter of 4 to 7 nm. An actin protein is the monomeric subunit of two types of filaments in cells: microfilaments, one of the three major components of the cytoskeleton, and thin filaments, part of the contractile apparatus in muscle cells. It can be present as either a free monomer called G-actin (globular) or as part of a linear polymer microfilament called F-actin (filamentous), both of which are essential for such important cellular functions as the mobility and contraction of cells during cell division. Actin participates in many important cellular processes, including muscle contraction, cell motility, cell division and cytokinesis, vesicle and organelle movement, cell sign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoskeleton
The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is composed of similar proteins in the various organisms. It is composed of three main components, microfilaments, intermediate filaments and microtubules, and these are all capable of rapid growth or disassembly dependent on the cell's requirements. A multitude of functions can be performed by the cytoskeleton. Its primary function is to give the cell its shape and mechanical resistance to deformation, and through association with extracellular connective tissue and other cells it stabilizes entire tissues. The cytoskeleton can also contract, thereby deforming the cell and the cell's environment and allowing cells to migrate. Moreover, it is involved in many cell signaling pathways and in the uptake of extracellular material ( endocytosis), the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
