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S6K2
Ribosomal protein S6 kinase beta-1 (S6K1), also known as p70S6 kinase (p70S6K, p70-S6K), is an enzyme (specifically, a protein kinase) that in humans is encoded by the ''RPS6KB1'' gene. It is a serine/threonine kinase that acts downstream of PIP3 and phosphoinositide-dependent kinase-1 in the PI3 kinase pathway. As the name suggests, its target substrate is the S6 ribosomal protein. Phosphorylation of S6 induces protein synthesis at the ribosome. The phosphorylation of p70S6K at threonine 389 has been used as a hallmark of activation by mTOR and correlated with autophagy inhibition in various situations. However, several recent studies suggest that the activity of p70S6K plays a more positive role in the increase of autophagy. Function This gene encodes a member of the S6K family of serine/threonine kinases, which phosphorylate several residues of the S6 ribosomal protein. The kinase activity of this protein leads to an increase in protein synthesis and cell proliferation. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribosomal Protein S6
Ribosomal protein S6 (rpS6 or eS6) is a component of the 40S ribosomal subunit and is therefore involved in translation. Mouse model studies have shown that phosphorylation of eS6 is involved in the regulation of cell size, cell proliferation, and glucose homeostasis. Studies show that the p70 ribosomal protein S6 kinases (S6K1 Ribosomal protein S6 kinase beta-1 (S6K1), also known as p70S6 kinase (p70S6K, p70-S6K), is an enzyme (specifically, a protein kinase) that in humans is encoded by the ''RPS6KB1'' gene. It is a serine/threonine kinase that acts downstream of PIP3 ... and S6K2) and p90 ribosomal protein S6 kinases ( RSK) both phosphorylate eS6 and that S6K1 and S6K2 predominate this function. Pathways leading to the induction of human eS6 phosphorylation have been found to enhance IL-8 protein synthesis. This mechanism is dependent on A/U-rich proximal sequences (APS) found in the 3'UTR of IL-8 immediately after the stop codon. References External links * * ... [...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] |
PI3K
Phosphoinositide 3-kinases (PI3Ks), also called phosphatidylinositol 3-kinases, are a family of enzymes involved in cellular functions such as cell growth, proliferation, differentiation, motility, survival and intracellular trafficking, which in turn are involved in cancer. PI3Ks are a family of related intracellular signal transducer enzymes capable of phosphorylating the 3 position hydroxyl group of the inositol ring of phosphatidylinositol (PtdIns). The pathway, with oncogene PIK3CA and tumor suppressor gene PTEN, is implicated in the sensitivity of cancer tumors to insulin and IGF1, and in calorie restriction. Discovery The discovery of PI3Ks by Lewis Cantley and colleagues began with their identification of a previously unknown phosphoinositide kinase associated with the polyoma middle T protein. They observed unique substrate specificity and chromatographic properties of the products of the lipid kinase, leading to the discovery that this phosphoinositide kinase had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CSNK2B
Casein kinase II subunit beta is a protein that in humans is encoded by the ''CSNK2B'' gene. This gene encodes the beta subunit of casein kinase II, a ubiquitous protein kinase which regulates metabolic pathways, signal transduction, transcription, translation, and replication. The enzyme localizes to the endoplasmic reticulum and the Golgi apparatus. Casein kinase, a ubiquitous, well-conserved protein kinase involved in cell metabolism and differentiation, is characterised by its preference for Serine or Threonine in acidic stretches of amino acids. The enzyme is a tetramer of 2 alpha- and 2 beta-subunits. However, some species (e.g., mammals) possess 2 related forms of the alpha-subunit (alpha and alpha'), while others (e.g., fungi) possess 2 related beta-subunits (beta and beta'). The alpha-subunit is the catalytic unit and contains regions characteristic of serine/threonine protein kinases. The beta-subunit is believed to be regulatory, possessing an N-terminal auto-phosphory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
COASY
Bifunctional coenzyme A synthase is an enzyme that in mammals is encoded by the ''COASY'' gene that catalyses the synthesis of coenzyme A from 4'-phosphopantetheine. Function COASY is an enzyme that catalyzes the last two steps in the synthesis of coenzyme A from vitamin B5 (pantothenic acid). The primary substrate is 4'-phosphopantetheine and COASY is a bifunctional enzyme in this pathway: * 4′-Phosphopantetheine is adenylated to form dephospho-CoA by the enzyme phosphopantetheine adenylyl-transferase (PPAT; CoaD) * Next, dephospho-CoA is phosphorylated to coenzyme A by the enzyme dephospho-CoA kinase (DPCK; CoaE) In mammals this is a single enzyme, but in organisms including yeast and bacteria these enzymes are encoded by separate genes. Interactions COASY has been shown to interact with P70-S6 Kinase 1. In 2009, COASY has also been implicated in PI3K signaling, as it was shown to interact with a regulatory subunit of PI3K. Clinical significance Loss of function mutati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EIF4B
Eukaryotic translation initiation factor 4B is a protein that in humans is encoded by the ''EIF4B'' gene. Interactions eIF4B has been shown to interact with and stimulate the activity of eIF4A and bind to the eIF3 complex through the eIF3A subunit. This interaction results in the recruitment of the eukaryotic small ribosomal subunit (40S) to the mRNA which will in turn set the stage for the later steps leading to elongation. See also *Eukaryotic translation *eIF4F Eukaryotic initiation factor 4F (eIF4F) is a heterotrimeric protein complex that binds the 5' cap of messenger RNAs (mRNAs) to promote eukaryotic translation initiation. The eIF4F complex is composed of three non-identical subunits: the DEAD- ... References Further reading * * * * * * * * * * * * * * * * * * {{gene-12-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RPTOR
Regulatory-associated protein of mTOR also known as raptor or KIAA1303 is an adapter protein that is encoded in humans by the ''RPTOR'' gene. Two mRNAs from the gene have been identified that encode proteins of 1335 (isoform 1) and 1177 (isoform 2) amino acids long. Gene and expression The human gene is located on human chromosome 17 with location of the cytogenic band at 17q25.3. Location RPTOR is highly expressed in skeletal muscle and is somewhat less present in brain, lung, small intestine, kidney, and placenta tissue. Isoform 3 is widely expressed and most highly expressed in the nasal mucosa and pituitary. The lowest levels occur in the spleen. In the cell, RPTOR is present in cytoplasm, lysosomes, and cytoplasmic granules. Amino acid availability determines RPTOR targeting to lysosomes. In stressed cells, RPTOR associates with SPAG5 and accumulates in stress granules, which significantly reduces its presence in lysosomes. Function ''RPTOR'' encodes part of a sign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryotic Initiation Factor 3
Eukaryotic initiation factor 3 (eIF3) is a multiprotein complex that functions during the initiation phase of eukaryotic translation. It is essential for most forms of cap-dependent and cap-independent translation initiation. In humans, eIF3 consists of 13 nonidentical subunits (eIF3a-m) with a combined molecular weight of ~800 kDa, making it the largest translation initiation factor. The eIF3 complex is broadly conserved across eukaryotes, but the conservation of individual subunits varies across organisms. For instance, while most mammalian eIF3 complexes are composed of 13 subunits, budding yeast's eIF3 has only six subunits (eIF3a, b, c, g, i, j). Function eIF3 stimulates nearly all steps of translation initiation. eIF3 also appears to participate in other phases of translation, such as recycling, where it promotes the splitting of post-termination ribosomes. In specialized cases of reinitiation following uORFs, eIF3 may remain bound to the ribosome through elongation a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soleus Muscle
In humans and some other mammals, the soleus is a powerful muscle in the back part of the lower leg (the calf). It runs from just below the knee to the heel, and is involved in standing and walking. It is closely connected to the gastrocnemius muscle and some anatomists consider them to be a single muscle, the triceps surae. Its name is derived from the Latin word "solea", meaning "sandal". Structure The soleus is located in the superficial posterior compartment of the leg. The soleus exhibits significant morphological differences across species. It is unipennate in many species. In some animals, such as the rabbit, it is fused for much of its length with the gastrocnemius muscle. In humans, the soleus is a complex, multi-pennate muscle, usually having a separate (posterior) aponeurosis from the gastrocnemius muscle. A majority of soleus muscle fibers originate from each side of the anterior aponeurosis, attached to the tibia and fibula. Other fibers originate from the posteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorylated
In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. Protein phosphorylation often activates (or deactivates) many enzymes. Glucose Phosphorylation of sugars is often the first stage in their catabolism. Phosphorylation allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter. Phosphorylation of glucose is a key reaction in sugar metabolism. The chemical equation for the conversion of D-glucose to D-glucose-6-phosphate in the first step of glycolysis is given by :D-glucose + ATP → D-glucose-6-phosphate + ADP : ΔG° = −16.7 kJ/mol (° indicates measurement at standard condition) Hepatic cells are freely permeable to glucose, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Culture
Cell culture or tissue culture is the process by which cells are grown under controlled conditions, generally outside of their natural environment. The term "tissue culture" was coined by American pathologist Montrose Thomas Burrows. This technique is also called micropropagation. After the cells of interest have been isolated from living tissue, they can subsequently be maintained under carefully controlled conditions the need to be kept at body temperature (37 °C) in an incubator. These conditions vary for each cell type, but generally consist of a suitable vessel with a substrate or rich medium that supplies the essential nutrients (amino acids, carbohydrates, vitamins, minerals), growth factors, hormones, and gases ( CO2, O2), and regulates the physio-chemical environment (pH buffer, osmotic pressure, temperature). Most cells require a surface or an artificial substrate to form an adherent culture as a monolayer (one single-cell thick), whereas others can be grown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
