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Protein Kinase R
Protein kinase RNA-activated also known as protein kinase R (PKR), interferon-induced, double-stranded RNA-activated protein kinase, or eukaryotic translation initiation factor 2-alpha kinase 2 (EIF2AK2) is an enzyme that in humans is encoded by the ''EIF2AK2'' gene on chromosome 2. PKR is a serine/tyrosine kinase that is 551 amino acids long. PKR is inducible by various mechanisms of stress and protects against viral infections. It also has a role in several signaling pathways. Mechanism of action Protein kinase-R is activated by double-stranded RNA (dsRNA), introduced to the cells by a viral infection. In situations of viral infection, the dsRNA created by viral replication and gene expression binds to the N-terminal domain, activating the protein. PKR activation via dsRNA is length dependent, requiring the dsRNA to be 30 bp in length to bind to PKR molecules. However, excess dsRNA can diminish activation of PKR. Binding to dsRNA is believed to activate PKR by inducing d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), 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, 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 include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FADD
FAS-associated death domain protein, also called MORT1, is encoded by the ''FADD'' gene on the 11q13.3 region of chromosome 11 in humans. FADD is an Signal transducing adaptor protein, adaptor protein that bridges members of the Tumor necrosis factor receptor, tumor necrosis factor receptor superfamily, such as the FasR, Fas-receptor, to caspase 8, procaspases 8 and caspase 10, 10 to form the death-inducing signaling complex (DISC) during apoptosis. As well as its most well known role in apoptosis, FADD has also been seen to play a role in other processes including proliferation, cell cycle regulation and development. Structure FADD is a 23 kDa protein, made up of 208 amino acids. It contains two main domains: a C terminal death domain (DD) and an N terminal death effector domain (DED). Each domain, although sharing very little sequence similarity, are structurally similar to one another, with each consisting of 6 α helices. The DD of FADD binds to receptors such as the Fas r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IRS1
Insulin receptor substrate 1 (IRS-1) is a signaling adapter protein that in humans is encoded by the ''IRS1'' gene. It is a 180 kDa protein with amino acid sequence of 1242 residues. It contains a single pleckstrin homology (PH) domain at the N-terminus and a PTB domain ca. 40 residues downstream of this, followed by a poorly conserved C-terminus tail. Together with IRS2, IRS3 (pseudogene) and IRS4, it is homologous to the ''Drosophila'' protein ''chico'', whose disruption extends the median lifespan of flies up to 48%. Similarly, Irs1 mutant mice experience moderate life extension and delayed age-related pathologies. Function Insulin receptor substrate 1 plays a key role in transmitting signals from the insulin receptor (IR) and insulin-like growth factor 1 receptor (IGF-1) to intracellular pathways PI3K / Akt and Erk MAP kinase pathways. Tyrosine phosphorylation of IRS-1 by insulin receptor (IR) introduces multiple binding sites for proteins bearing SH2 homology domai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulin
Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the insulin (''INS)'' gene. It is the main Anabolism, anabolic hormone of the body. It regulates the metabolism of carbohydrates, fats, and protein by promoting the absorption of glucose from the blood into cells of the liver, fat cell, fat, and skeletal muscles. In these tissues the absorbed glucose is converted into either glycogen, via glycogenesis, or Fatty acid metabolism#Glycolytic end products are used in the conversion of carbohydrates into fatty acids, fats (triglycerides), via lipogenesis; in the liver, glucose is converted into both. Glucose production and secretion by the liver are strongly inhibited by high concentrations of insulin in the blood. Circulating insulin also affects the synthesis of proteins in a wide variety of tissues. It is thus an anabolic hormone, promoting the conversion of small molecules in the blood into large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P38 Mitogen-activated Protein Kinases
p38 mitogen-activated protein kinases are a class of mitogen-activated protein kinases (MAPKs) that are responsive to stress stimuli, such as cytokines, ultraviolet irradiation, heat shock, and osmotic shock, and are involved in cell differentiation, apoptosis and autophagy. Persistent activation of the p38 MAPK pathway in muscle satellite cells (muscle stem cells) due to ageing, impairs muscle regeneration. p38 MAP Kinase (MAPK), also called RK or CSBP (Cytokinin Specific Binding Protein), is the mammalian orthologue of the yeast Hog1p MAP kinase, which participates in a signaling cascade controlling cellular responses to cytokines and stress. Four p38 MAP kinases, p38-α ( MAPK14), -β ( MAPK11), -γ ( MAPK12 / ERK6), and -δ ( MAPK13 / SAPK4), have been identified. Similar to the SAPK/JNK pathway, p38 MAP kinase is activated by a variety of cellular stresses including osmotic shock, inflammatory cytokines, lipopolysaccharides (LPS), ultraviolet light, and growth fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ER Stress
The unfolded protein response (UPR) is a cellular stress response related to the endoplasmic reticulum (ER) stress. It has been found to be conserved between mammalian species, as well as yeast and worm organisms. The UPR is activated in response to an accumulation of unfolded or misfolded proteins in the lumen of the endoplasmic reticulum. In this scenario, the UPR has three aims: initially to restore normal function of the cell by halting protein translation, degrading misfolded proteins, and activating the signaling pathways that lead to increasing the production of molecular chaperones involved in protein folding. If these objectives are not achieved within a certain time span or the disruption is prolonged, the UPR aims towards apoptosis. Sustained overactivation of the UPR has been implicated in prion diseases as well as several other neurodegenerative diseases, and inhibiting the UPR could become a treatment for those diseases. Diseases amenable to UPR inhibition include Cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irradiation
Irradiation is the process by which an object is exposed to radiation. An irradiator is a device used to expose an object to radiation, most often gamma radiation, for a variety of purposes. Irradiators may be used for sterilizing medical and pharmaceutical supplies, preserving foodstuffs, alteration of gemstone colors, studying radiation effects, eradicating insects through sterile male release programs, or calibrating thermoluminescent dosimeters (TLDs). The exposure can originate from various sources, including natural sources. Most frequently the term refers to ionizing radiation, and to a level of radiation that will serve a specific purpose, rather than radiation exposure to normal levels of background radiation. The term irradiation usually excludes the exposure to non-ionizing radiation, such as infrared, visible light, microwaves from cellular phones or electromagnetic waves emitted by radio and television receivers and power supplies. Applications Sterilization If ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Figure Of PKR Signalling Pathways
Figure may refer to: General *A shape, drawing, depiction, or geometric configuration *Figure (wood), wood appearance *Figure (music), distinguished from musical motif *Noise figure, in telecommunication *Dance figure, an elementary dance pattern *A person's figure, human physical appearance *Figure–ground (perception), the distinction between a visually perceived object and its surroundings Arts *Figurine, a miniature statuette representation of a creature *Action figure, a posable jointed solid plastic character figurine *Figure painting, realistic representation, especially of the human form *Figure drawing *Model figure, a scale model of a creature Writing *figure, in writing, a type of floating block (text, table, or graphic separate from the main text) *Figure of speech, also called a rhetorical figure *Christ figure, a type of character * in typesetting, text figures and lining figures Accounting *Figure, a synonym for number *Significant figures in a decimal number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autophagy
Autophagy (or autophagocytosis; from the Greek language, Greek , , meaning "self-devouring" and , , meaning "hollow") is the natural, conserved degradation of the cell that removes unnecessary or dysfunctional components through a lysosome-dependent regulated mechanism. It allows the orderly degradation and recycling of cellular components. Although initially characterized as a primordial degradation pathway induced to protect against starvation, it has become increasingly clear that autophagy also plays a major role in the homeostasis of non-starved cells. Defects in autophagy have been linked to various human diseases, including neurodegeneration and cancer, and interest in modulating autophagy as a potential treatment for these diseases has grown rapidly. Four forms of autophagy have been identified: macroautophagy, microautophagy, chaperone-mediated autophagy (CMA), and crinophagy. In macroautophagy (the most thoroughly researched form of autophagy), cytoplasmic components ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PP2A
Protein phosphatase 2 (PP2), also known as PP2A, is an enzyme that in humans is encoded by the ''PPP2CA'' gene. The PP2A heterotrimeric protein phosphatase is ubiquitously expressed, accounting for a large fraction of phosphatase activity in eukaryotic cells. Its serine/threonine phosphatase activity has a broad substrate specificity and diverse cellular functions. Among the targets of PP2A are proteins of oncogenic signaling cascades, such as Raf, MEK, and AKT, where PP2A may act as a tumor suppressor. Structure and function PP2A consists of a dimeric core enzyme composed of the structural A and catalytic C subunits, and a regulatory B subunit. When the PP2A catalytic C subunit associates with the A and B subunits several species of holoenzymes are produced with distinct functions and characteristics. The A subunit, a founding member of the HEAT repeat protein family (huntingtin, EF3, PP2A, TOR1), is the scaffold required for the formation of the heterotrimeric compl ... [...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] |
