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P53 Upregulated Modulator Of Apoptosis
The p53 upregulated modulator of apoptosis (PUMA) also known as Bcl-2-binding component 3 (BBC3), is a pro- apoptotic protein, member of the Bcl-2 protein family. In humans, the Bcl-2-binding component 3 protein is encoded by the ''BBC3'' gene. The expression of PUMA is regulated by the tumor suppressor p53. PUMA is involved in p53-dependent and -independent apoptosis induced by a variety of signals, and is regulated by transcription factors, not by post-translational modifications. After activation, PUMA interacts with antiapoptotic Bcl-2 family members, thus freeing Bax and/or Bak which are then able to signal apoptosis to the mitochondria. Following mitochondrial dysfunction, the caspase cascade is activated ultimately leading to cell death. Structure The PUMA protein is part of the BH3-only subgroup of Bcl-2 family proteins. This group of proteins only share sequence similarity in the BH3 domain, which is required for interactions with Bcl-2-like proteins, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosis
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, DNA fragmentation, and mRNA decay. The average adult human loses between 50 and 70 billion cells each day due to apoptosis. For an average human child between eight and fourteen years old, approximately twenty to thirty billion cells die per day. In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo occurs because cells between the digits undergo apoptosis. Unlike necrosis, apoptosis produces cell fragments called apoptotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosis-inducing Factor
Apoptosis inducing factor is involved in initiating a caspase-independent pathway of apoptosis (positive intrinsic regulator of apoptosis) by causing DNA fragmentation and chromatin condensation. Apoptosis inducing factor is a flavoprotein. It also acts as an NADH oxidase. Another AIF function is to regulate the permeability of the mitochondrial membrane upon apoptosis. Normally it is found behind the outer membrane of the mitochondrion and is therefore secluded from the nucleus. However, when the mitochondrion is damaged, it moves to the cytosol and to the nucleus. Inactivation of AIF leads to resistance of embryonic stem cells to death following the withdrawal of growth factors indicating that it is involved in apoptosis. Function Apoptosis Inducing Factor (AIF) is a protein that triggers chromatin condensation and DNA fragmentation in a cell in order to induce programmed cell death. The mitochondrial AIF protein was found to be a caspase-independent death effector that ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infection
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disease, is an illness resulting from an infection. Infections can be caused by a wide range of pathogens, most prominently bacteria and viruses. Hosts can fight infections using their immune system. Mammalian hosts react to infections with an innate response, often involving inflammation, followed by an adaptive response. Specific medications used to treat infections include antibiotics, antivirals, antifungals, antiprotozoals, and antihelminthics. Infectious diseases resulted in 9.2 million deaths in 2013 (about 17% of all deaths). The branch of medicine that focuses on infections is referred to as infectious disease. Types Infections are caused by infectious agents (pathogens) including: * Bacteria (e.g. ''Mycobacterium tuberculosis'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune
In biology, immunity is the capability of multicellular organisms to resist harmful microorganisms. Immunity involves both specific and nonspecific components. The nonspecific components act as barriers or eliminators of a wide range of pathogens irrespective of their antigenic make-up. Other components of the immune system adapt themselves to each new disease encountered and can generate pathogen-specific immunity. Immunity is a complex biological system that can recognize and tolerate whatever belongs to the self, and to recognize and reject what is foreign (non-self). Innate and adaptive Innate Immunity First off, the immune system is a system in the body of animals that enables animals to avoid or limit many infections caused by pathogens. Pathogens are disease causing agents, causing a wide range of illnesses. As for Diseases it's when structure of an organism is negatively affected other than external injury. Both diseases and pathogens affect the immune system causing ill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ischemia
Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems with blood vessels, with resultant damage to or dysfunction of tissue i.e. hypoxia and microvascular dysfunction. It also implies local hypoxia in a part of a body resulting from constriction (such as vasoconstriction, thrombosis, or embolism). Ischemia causes not only insufficiency of oxygen, but also reduced availability of nutrients and inadequate removal of metabolic wastes. Ischemia can be partial (poor perfusion) or total blockage. The inadequate delivery of oxygenated blood to the organs must be resolved either by treating the cause of the inadequate delivery or reducing the oxygen demand of the system that needs it. For example, patients with myocardial ischemia have a decreased blood flow to the heart and are prescribed with medi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redox
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate (chemistry), substrate change. Oxidation is the loss of Electron, electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endoplasmic Reticulum
The endoplasmic reticulum (ER) is, in essence, the transportation system of the eukaryotic cell, and has many other important functions such as protein folding. It is a type of organelle made up of two subunits – rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER). The endoplasmic reticulum is found in most eukaryotic cells and forms an interconnected network of flattened, membrane-enclosed sacs known as cisternae (in the RER), and tubular structures in the SER. The membranes of the ER are continuous with the outer nuclear membrane. The endoplasmic reticulum is not found in red blood cells, or spermatozoa. The two types of ER share many of the same proteins and engage in certain common activities such as the synthesis of certain lipids and cholesterol. Different types of cells contain different ratios of the two types of ER depending on the activities of the cell. RER is found mainly toward the nucleus of cell and SER towards the cell membrane or plasma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinase
In biochemistry, a kinase () is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule donates a phosphate group to the substrate molecule. This transesterification produces a phosphorylated substrate and ADP. Conversely, it is referred to as dephosphorylation when the phosphorylated substrate donates a phosphate group and ADP gains a phosphate group (producing a dephosphorylated substrate and the high energy molecule of ATP). These two processes, phosphorylation and dephosphorylation, occur four times during glycolysis. Kinases are part of the larger family of phosphotransferases. Kinases should not be confused with phosphorylases, which catalyze the addition of inorganic phosphate groups to an acceptor, nor with phosphatases, which remove phosphate groups (dephosphorylation). The phosphorylation state of a molecule, whet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytokine
Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrine, paracrine and endocrine signaling as immunomodulating agents. Cytokines include chemokines, interferons, interleukins, lymphokines, and tumour necrosis factors, but generally not hormones or growth factors (despite some overlap in the terminology). Cytokines are produced by a broad range of cells, including immune cells like macrophages, B lymphocytes, T lymphocytes and mast cells, as well as endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. They act through cell surface receptors and are especially important in the immune system; cytokines modulate the balance between humoral and cell-based immune responses, and they regulate the maturation, growth, and res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Factor
A growth factor is a naturally occurring substance capable of stimulating cell proliferation, wound healing, and occasionally cellular differentiation. Usually it is a secreted protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes. Growth factors typically act as signaling molecules between cells. Examples are cytokines and hormones that bind to specific receptors on the surface of their target cells. They often promote cell differentiation and maturation, which varies between growth factors. For example, epidermal growth factor (EGF) enhances osteogenic differentiation, while fibroblast growth factors and vascular endothelial growth factors stimulate blood vessel differentiation (angiogenesis). Comparison to cytokines ''Growth factor'' is sometimes used interchangeably among scientists with the term ''cytokine.'' Historically, cytokines were associated with hematopoietic (blood and lymph forming) cells and immune syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription (genetics)
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). mRNA comprises only 1–3% of total RNA samples. Less than 2% of the human genome can be transcribed into mRNA ( Human genome#Coding vs. noncoding DNA), while at least 80% of mammalian genomic DNA can be actively transcribed (in one or more types of cells), with the majority of this 80% considered to be ncRNA. Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. Transcription proceeds in the following general steps: # RNA polymerase, together with one or more general transcription factors, binds to promoter DNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteasome Inhibitor
Proteasome inhibitors are drugs that block the action of proteasomes, cellular complexes that break down proteins. They are being studied in the treatment of cancer; and three are approved for use in treating multiple myeloma. Mechanism Multiple mechanisms are likely to be involved, but proteasome inhibition may prevent degradation of pro-apoptotic factors such as the p53 protein, permitting activation of programmed cell death in neoplastic cells dependent upon suppression of pro-apoptotic pathways. For example, bortezomib causes a rapid and dramatic change in the levels of intracellular peptides. Examples * The first non-peptidic proteasome inhibitor discovered was the natural product lactacystin. * Disulfiram has been proposed as another proteasome inhibitor. * Epigallocatechin-3-gallate has also been proposed. * Marizomib (salinosporamide A) has started clinical trials for multiple myeloma. * Oprozomib (ONX-0912), delanzomib (CEP-18770) have also started clinical trials. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
