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DDX58
RIG-I (retinoic acid-inducible gene I) is a cytosolic pattern recognition receptor (PRR) that can mediate induction of a type-I 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 an ATP-dependent DExD/H box RNA helicase that is activated by immunostimulatory RNAs from viruses as well as RNAs of other origins. RIG-I recognizes short double-stranded RNA (dsRNA) in the cytosol with a 5' tri- or di-phosphate end or a 5' 7-methyl guanosine (m7G) cap (cap-0), but not RNA with a 5' m7G cap having a ribose 2′-O-methyl modification (cap-1). These are often generated during a viral infection but can also be host-derived. Once activated by the dsRNA, the N-terminus caspase activation and recruitment domains (CARDs) migrate and bind with CARDs attached to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RIG-I-like Receptor
RIG-I-like receptors (retinoic acid-inducible gene-I-like receptors, RLRs) are a type of Intracellular receptor, 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. Probable ATP-dependent RNA helicase DHX58, LGP2 binds to blunt-ended double-stranded RNA of variable length, and also to RNA-bound MDA5 to regulate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Helicase
Helicases are a class of enzymes that are 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 double helix, separating the two hybridized nucleic acid strands (hence '' helic- + -ase''), via the energy gained 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 viral nucleic acids during infection and fulfill an immunological function. Genetic mutations that affect helicases ... [...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. CARDs are found on a strikingly wide range of proteins, including helicases, kinases, mitochondrial proteins, caspases, and other cytoplasmic factors. Basic features CARDs 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 CARDs were originally characterized based on their involvement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytosol
The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells ( intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondrion into many compartments. In the eukaryotic cell, the cytosol is surrounded by the cell membrane and is part of the cytoplasm, which also comprises the mitochondria, plastids, and other organelles (but not their internal fluids and structures); the cell nucleus is separate. The cytosol is thus a liquid matrix around the organelles. In prokaryotes, most of the chemical reactions of metabolism take place in the cytosol, while a few take place in membranes or in the periplasmic space. In eukaryotes, while many metabolic pathways still occur in the cytosol, others take place within organelles. The cytosol is a complex mixture of substances dissolved in water. Although water forms the large majority of the cytosol, its structure and proper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STING
Stimulator of interferon genes (STING), also known as transmembrane protein 173 (TMEM173) and MPYS/MITA/ERIS is a regulator protein that in humans is encoded by the STING1 gene. STING plays an important role in innate immunity. STING induces type I interferon production when cells are infected with intracellular pathogens, such as viruses, mycobacteria and intracellular parasites. Type I interferon, mediated by STING, protects infected cells and nearby cells from local infection by binding to the same cell that secretes it (autocrine signaling) and nearby cells (paracrine signaling.) It thus plays an important role, for instance, in controlling norovirus infection. STING works as both a direct cytosolic DNA sensor (CDS) and an adaptor protein in Type I interferon signaling through different molecular mechanisms. It has been shown to activate downstream transcription factors STAT6 and IRF3 through TBK1, which are responsible for antiviral response and innate immune response aga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pathogen-associated Molecular Pattern
Pathogen-associated molecular patterns (PAMPs) are small molecular motifs conserved within a class of microbes, but not present in the host. They are recognized by toll-like receptors (TLRs) and other pattern recognition receptors (PRRs) in both plants and animals. This allows the innate immune system to recognize pathogens and thus, protect the host from infection. This initiation of the immune response consists of the secretion of inflammatory cytokines and chemokines. PAMPs can initiate the maturation of immune cells, which can travel to the primary lymph node and trigger the adaptive immune system that involves the production of antibodies against specific antigens. Although the term "PAMP" is relatively new, the concept that molecules derived from microbes must be detected by receptors from multicellular organisms has been held for many decades, and references to an "endotoxin receptor" are found in much of the older literature. The recognition of PAMPs by the PRRs triggers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus
A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898, more than 16,000 of the millions of List of virus species, virus species have been described in detail. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent viral particles, or ''virions'', consisting of (i) genetic material, i.e., long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pattern Recognition Receptor
Pattern recognition receptors (PRRs) play a crucial role in the proper function of the innate immune system. PRRs are germline-encoded host sensors, which detect molecules typical for the pathogens. They are proteins expressed mainly by cells of the innate immune system, such as dendritic cells, macrophages, monocytes, neutrophils, as well as by epithelial cells, to identify two classes of molecules: pathogen-associated molecular patterns (PAMPs), which are associated with microbial pathogens, and damage-associated molecular patterns (DAMPs), which are associated with components of host's cells that are released during cell damage or death. They are also called primitive pattern recognition receptors because they evolved before other parts of the immune system, particularly before adaptive immunity. PRRs also mediate the initiation of antigen-specific adaptive immune response and release of inflammatory cytokines. PRRs are regulated through a variety of pathways ensure optimal im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VISA (gene)
Mitochondrial antiviral-signaling protein (MAVS) is a protein that is essential for antiviral Innate immune system, innate immunity. MAVS is located in the outer membrane of the mitochondria, peroxisomes, and Mitochondria associated membranes, mitochondrial-associated endoplasmic reticulum membrane (MAM). Upon viral infection, a group of Cytosol, cytosolic proteins will detect the presence of the virus and bind to MAVS, thereby activating MAVS. The activation of MAVS leads the virally infected cell to secrete cytokines. This induces an immune response which kills the host's virally infected cells, resulting in clearance of the virus. Structure MAVS is also known as IFN-β promoter stimulator I (IPS-1), caspase activation recruitment domain adaptor inducing IFN-β (CARDIF), or virus induced signaling adaptor (VISA). MAVS is encoded by a ''MAVS'' gene. MAVS is a 540 amino acid protein that consists of three components, a N terminal caspase activation recruitment domain (CARD), a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LGP2
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 In coordination chemistry, a ligand is an ion or molecule with a functional group that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MDA5
MDA5 (melanoma differentiation-associated protein 5) is a RIG-I-like receptor dsRNA helicase 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 CARD domain. Some observations made in cancer cells show that MDA5 also interacts with cellular RNA is able to induce an autoinflammatory response. Function As a pattern recognition receptor MDA5 is able to detect long dsRNA, the genomic RNA of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
