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Probable ATP-dependent RNA Helicase DHX58
Probable ATP-dependent RNA helicase DHX58 also known as RIG-I-like receptor 3 (RLR-3) or RIG-I-like receptor LGP2 (RLR) is a RIG-I-like receptor dsRNA helicase enzyme that in humans is encoded by the ''DHX58'' gene. The protein encoded by the gene DHX58 is known as LGP2 (Laboratory of Genetics and Physiology 2). Structure and function LGP2 was first identified and characterized in the context of mammary tissue in 2001, but its function has been found to be more relevant to the field of innate antiviral immunity. LGP2 has been found to be essential for producing effective antiviral responses against many viruses that are recognized by RIG-I and MDA5. Since LGP2 lacks CARD domains, its effect on downstream antiviral signaling is likely due to interaction with dsRNA viral ligand or the other RLRs (RIG-I and MDA5). LGP2 has been shown to directly interact with RIG-I through its C-terminal repressor domain (RD). The primary contact sites in this interaction is likely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RIG-I-like Receptor
RIG-like receptors (retinoic acid-inducible gene-I-like receptors, RLRs) are a type of intracellular pattern recognition receptor involved in the recognition of viruses by the innate immune system. RIG-I (retinoic-acid inducible gene or DDX58) is the best characterized receptor within the RIG-I like receptor (RLR) family. Together with MDA5 (melanoma differentiation-associated 5) and LGP2 (laboratory of genetics and physiology 2), this family of cytoplasmic pattern recognition receptors (PRRs) are sentinels for intracellular viral RNA that is a product of viral infection. The RLR receptors provide frontline defence against viral infections in most tissues. RLR ligands The RIG-I receptor prefers to bind short (2000 bp), such as the replicative form of picornavirus RNA that is found in picornavirus-infected cells. LGP2 binds to blunt-ended double-stranded RNA of variable length, and also to RNA-bound MDA5 to regulate filament formation. The latter is linked to LGP2's recognition of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DsRNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydrates, nucleic acids constitute one of the four major macromolecules essential for all known forms of life. Like DNA, RNA is assembled as a chain of nucleotides, but unlike DNA, RNA is found in nature as a single strand folded onto itself, rather than a paired double strand. Cellular organisms use messenger RNA (''mRNA'') to convey genetic information (using the nitrogenous bases of guanine, uracil, adenine, and cytosine, denoted by the letters G, U, A, and C) that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome. Some RNA molecules play an active role within cells by catalyzing biological reactions, controlling gene expression, or sensing and communicating responses to cellular signa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicase
Helicases are a class of enzymes thought to be vital to all organisms. Their main function is to unpack an organism's genetic material. Helicases are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separating two hybridized nucleic acid strands (hence '' helic- + -ase''), using energy from ATP hydrolysis. There are many helicases, representing the great variety of processes in which strand separation must be catalyzed. Approximately 1% of eukaryotic genes code for helicases. The human genome codes for 95 non-redundant helicases: 64 RNA helicases and 31 DNA helicases. Many cellular processes, such as DNA replication, transcription, translation, recombination, DNA repair, and ribosome biogenesis involve the separation of nucleic acid strands that necessitates the use of helicases. Some specialized helicases are also involved in sensing of viral nucleic acids during infection and fulfill a immunological function. Function Helicases are o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...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] |
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] |
Mammary Tissue
A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in primates (for example, humans and chimpanzees), the udder in ruminants (for example, cows, goats, sheep, and deer), and the dugs of other animals (for example, dogs and cats). Lactorrhea, the occasional production of milk by the glands, can occur in any mammal, but in most mammals, lactation, the production of enough milk for nursing, occurs only in phenotypic females who have gestated in recent months or years. It is directed by hormonal guidance from sex steroids. In a few mammalian species, male lactation can occur. With humans, male lactation can occur only under specific circumstances. Mammals are divided into 3 groups: prototherians, metatherians, and eutherians. In the case of prototherians, both males and females have functional mamma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Innate Immune System
The innate, or nonspecific, immune system is one of the two main immunity strategies (the other being the adaptive immune system) in vertebrates. The innate immune system is an older evolutionary defense strategy, relatively speaking, and is the dominant immune system response found in plants, fungi, insects, and primitive multicellular organisms (see Beyond vertebrates).. The major functions of the innate immune system are to: * recruit immune cells to infection sites by producing chemical factors, including chemical mediators called cytokines * activate the complement cascade to identify bacteria, activate cells, and promote clearance of antibody complexes or dead cells * identify and remove foreign substances present in organs, tissues, blood and lymph, by specialized white blood cells * activate the adaptive immune system through antigen presentation * act as a physical and chemical barrier to infectious agents; via physical measures such as skin and chemical measures such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RIG-I
RIG-I (retinoic acid-inducible gene I) is a cytosolic pattern recognition receptor (PRR) responsible for the type-1 interferon (IFN1) response. RIG-I is an essential molecule in the innate immune system for recognizing cells that have been infected with a virus. These viruses can include West Nile virus, Japanese Encephalitis virus, influenza A, Sendai virus, flavivirus, and coronaviruses. RIG-I is structurally considered a helical ATP-dependent DExD/H box RNA helicase, that recognizes short viral double-stranded RNA (dsRNA) in the cytosol during a viral infection or other irregular RNAs (i.e., non-coding RNAs). Once activated by the dsRNA, the N-terminus caspase activation and recruitment domains (CARDs) migrate and bind with CARDs attached to mitochondrial antiviral signaling protein ( MAVS) to activate the signaling pathway for IFN1. IFN1s have three main functions: to limit the virus from spreading to nearby cells, promote an innate immune response, including inflammatory re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MDA5
MDA5 (melanoma differentiation-associated protein 5) is a RIG-I-like receptor dsRNA helicase Helicases are a class of enzymes thought to be vital to all organisms. Their main function is to unpack an organism's genetic material. Helicases are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separatin ... enzyme that is encoded by the ''IFIH1'' gene in humans. MDA5 is part of the RIG-I-like receptor (RLR) family, which also includes RIG-I and LGP2, and functions as a pattern recognition receptor capable of detecting viruses. It is generally believed that MDA5 recognizes double stranded RNA (dsRNA) over 2000nts in length, however it has been shown that whilst MDA5 can detect and bind to cytoplasmic dsRNA, it is also activated by a high molecular weight RNA complex composed of ssRNA and dsRNA. For many viruses, effective MDA5-mediated antiviral responses are dependent on functionally active LGP2. The signaling cascades in MDA5 is initiated via ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CARD Domain
Caspase recruitment domains, or caspase activation and recruitment domains (CARDs), are interaction motifs found in a wide array of proteins, typically those involved in processes relating to inflammation and apoptosis. These domains mediate the formation of larger protein complexes via direct interactions between individual CARDs. CARD domains are found on a strikingly wide range of proteins, including helicases, kinases, mitochondrial proteins, caspases, and other cytoplasmic factors. Basic features CARD domains are a subclass of protein motif known as the death fold, which features an arrangement of six to seven antiparallel alpha helices with a hydrophobic core and an outer face composed of charged residues. Other motifs in this class include the pyrin domain (PYD), death domain (DD), and death effector domain (DED), all of which also function primarily in regulation of apoptosis and inflammatory responses. In apoptosis CARD domains were originally characterized based on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand (biochemistry)
In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from ''ligare'', which means 'to bind'. In protein-ligand binding, the ligand is usually a molecule which produces a signal by binding to a site on a target protein. The binding typically results in a change of conformational isomerism (conformation) of the target protein. In DNA-ligand binding studies, the ligand can be a small molecule, ion, or protein which binds to the DNA double helix. The relationship between ligand and binding partner is a function of charge, hydrophobicity, and molecular structure. Binding occurs by intermolecular forces, such as ionic bonds, hydrogen bonds and Van der Waals forces. The association or docking is actually reversible through dissociation. Measurably irreversible covalent bonding between a ligand and target molecule is atypical in biological systems. In contrast to the definition of lig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
