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Sp100 Nuclear Antigen
Sp100 nuclear antigen is an interferon stimulated antigen found in the cell nuclei of many human and higher animal cells. Autoantibodies directed against Sp100 are often found in patients with primary biliary cirrhosis. Histologically Sp100 'dots' regions of the cell nucleus. Viral infection and mitogens affect the expression of the Sp100 autoantigen. Cells grown in the presence of interferons (α, β, and γ) revealed an increase both in size and number of the Sp100 protein-containing nuclear dots and increase the protein concentration. This raises "the question whether cytokine-mediated increase of Sp100 protein expression plays a role in induction of anti-Sp100 autoantibodies." Sp100 and nuclear dots Two proteins, Sp100 and promyelocytic leukemia ( PML) factor are localized to punctate domains in the nucleus ( nuclear dots or nuclear bodies). These domains (few to 20) were found to form a donut-shaped structure when cells were starved of amino acids. In particular, deprivati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferon
Interferons (IFNs, ) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten their anti-viral defenses. IFNs belong to the large class of proteins known as cytokines, molecules used for communication between cells to trigger the protective defenses of the immune system that help eradicate pathogens. Interferons are named for their ability to "interfere" with viral replication by protecting cells from virus infections. However, virus-encoded genetic elements have the ability to antagonize the IFN response, contributing to viral pathogenesis and viral diseases. IFNs also have various other functions: they activate immune cells, such as natural killer cells and macrophages, and they increase host defenses by up-regulating antigen presentation by virtue of increasing the expression of major histocompatibility compl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antigen
In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of simple sugars), lipids, or nucleic acids. Antigens exist on normal cells, cancer cells, parasites, viruses, fungus, fungi, and bacteria. Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, antibodies are ''antigen-specific'', meaning that an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Biliary Cirrhosis
Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is an autoimmune disease of the liver. It results from a slow, progressive destruction of the small bile ducts of the liver, causing bile and other toxins to build up in the liver, a condition called cholestasis. Further slow damage to the liver tissue can lead to scarring, fibrosis, and eventually cirrhosis. Common symptoms are tiredness, itching, and in more advanced cases, jaundice. In early cases, the only changes may be those seen in blood tests. PBC is a relatively rare disease, affecting up to one in 3,000–4,000 people. As with many other autoimmune diseases, it is much more common in women, with a sex ratio of at least 9:1 female to male. The reasons for this disparity are unclear, but may involve the expression of sex hormones such as estrogen, which impact immune system response. The condition has been recognised since at least 1851, and was named "primary biliary cirrhosis" i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitogens
A mitogen is a small bioactive protein or peptide that induces a cell to begin cell division, or enhances the rate of division (mitosis). Mitogenesis is the induction (triggering) of mitosis, typically via a mitogen. The cell cycle Mitogens act primarily by influencing a set of proteins which are involved in the restriction of progression through the cell cycle. The G1 checkpoint is controlled most directly by mitogens: further cell cycle progression does not need mitogens to continue. The point where mitogens are no longer needed to move the cell cycle forward is called the "restriction point" and depends on cyclins to be passed.Bohmer et al. "Cytoskeletal Integrity Is Required throughout the Mitogen Stimulation Phase of the Cell Cycle and Mediates the Anchorage-dependent Expression of Cyclin DI". January 1996, Molecular Biology of the Cell, Vol. 7, pp. 101-111. One of the most important of these is TP53, a gene which produces a family of proteins known as p53. It, combined wi ... [...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 produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes and mast cells, as well as Endothelium, endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. Due to their size, cytokines cannot cross the lipid bilayer of cells to enter the cytoplasm and therefore typically exert their functions by interacting with specific cytokine receptor, cytokine receptors on the target cell surface. Cytokines are especially important in the immune system; cytokines modulate the balance between humoral immunity, humoral and cell-mediated immunity, cell-based immune responses, and they regulate the maturation, growth, and responsiveness of particular cell populations. Some cytokines enhance or inhibit the action of other cytokines in complex way ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-sp100 Antibodies
Anti-sp100 antibodies are found in association with primary biliary cirrhosis. The autoimmune target of anti-sp100 is the sp100 nuclear antigen which was identified by its association with primary biliary cirrhosis Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is an autoimmune disease of the liver. It results from a slow, progressive destruction of the small bile ducts of the liver, causing bile and other toxins to buil .... 20-30% of patients with primary biliary cirrhosis have sp100 Abs. The sera of these patients exhibit a characteristic "nuclear dots" pattern in indirect immunofluorescence (IIF) on Hep-2 cells. Immunodominant regions of sp100 * Antigenic region 1 - positions 296-311 - Sequence (I K K E K P F S N S K V E C Q A) * Antigenic region 2 - positions 332-351 - Sequence (E G S T D V D E P L E V F I S A P R S E) (Bolded areas represent the core epitope.) References {{Autoantibodies Autoantibodies PBC autoantibodies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NUCLEAR DOTS
Nuclear bodies (also known as nuclear domains or nuclear dots) are biomolecular condensates, membraneless structures found in the cell nuclei of eukaryotic cells. Nuclear bodies include Cajal bodies, the nucleolus, nuclear speckles (also called splicing speckles), histone locus bodies, and promyelocytic leukemia protein (PML) nuclear bodies (also called PML oncogenic dots). Nuclear bodies also include ND10s. ND stands for nuclear domain, and 10 refers to the number of dots seen. Additionally, a nuclear body subtype is a clastosome suggested to be a site of protein degradation. While biomolecular condensate is a term often used interchangeably with nuclear bodies, the term "condensates" implies the thermodynamic properties of the body are known. Thus, nuclear body (and sometimes nuclear compartment) is a term that is more general and encompasses structures where either the biophysical property is not a condensate or is currently untested. Nuclear bodies were first seen as prom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Promyelocytic Leukemia Protein
Promyelocytic leukemia protein (PML) (also known as MYL, RNF71, PP8675 or TRIM19) is the protein product of the ''PML'' gene. PML protein is a tumor suppressor protein required for the assembly of a number of nuclear structures, called PML-nuclear bodies, which form amongst the chromatin of the cell nucleus. These nuclear bodies are present in mammalian nuclei, at about 1 to 30 per cell nucleus. PML-NBs are known to have a number of regulatory cellular functions, including involvement in programmed cell death, genome stability, antiviral effects and controlling cell division. PML mutation or loss, and the subsequent dysregulation of these processes, has been implicated in a variety of cancers. History PML was poorly understood until described in the findings of Grignani ''et al'' in their 1996 study of patients with acute promyelocytic leukemia (APL). It was found that the karyotype of 90% of APL patients included a reciprocal translocation, resulting in the fusion of the gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Dots
Nuclear bodies (also known as nuclear domains or nuclear dots) are biomolecular condensates, membraneless structures found in the cell nuclei of eukaryotic cells. Nuclear bodies include Cajal bodies, the nucleolus, nuclear speckles (also called splicing speckles), histone locus bodies, and promyelocytic leukemia protein (PML) nuclear bodies (also called PML oncogenic dots). Nuclear bodies also include ND10s. ND stands for nuclear domain, and 10 refers to the number of dots seen. Additionally, a nuclear body subtype is a clastosome suggested to be a site of protein degradation. While biomolecular condensate is a term often used interchangeably with nuclear bodies, the term "condensates" implies the thermodynamic properties of the body are known. Thus, nuclear body (and sometimes nuclear compartment) is a term that is more general and encompasses structures where either the biophysical property is not a condensate or is currently untested. Nuclear bodies were first seen as prom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Small Ubiquitin-related Modifier 1
Small ubiquitin-related modifier 1 is a protein that in humans is encoded by the ''SUMO1'' gene. Function This gene encodes a protein that is a member of the SUMO (small ubiquitin-like modifier) protein family. It is a ubiquitin-like protein and functions in a manner similar to ubiquitin in that it is bound to target proteins as part of a post-translational modification system. However, unlike ubiquitin, which is primarily associated with targeting proteins for proteasomal degradation, SUMO1 is involved in a variety of cellular processes, such as nuclear transport, transcriptional regulation, apoptosis, and protein stability. It is not active until the last four amino acids of the carboxy-terminus have been cleaved off. Several pseudogenes have been reported for this gene. Alternate transcriptional splice variants encoding different isoforms have been characterized. Most cleft genes have a sumoylation component. Analysis of chromosomal anomalies in patients has led to the ide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Pore
The nuclear pore complex (NPC), is a large protein complex giving rise to the nuclear pore. A great number of nuclear pores are studded throughout the nuclear envelope that surrounds the eukaryote cell nucleus. The pores enable the nuclear transport of macromolecules between the nucleoplasm of the nucleus and the cytoplasm of the Cell (biology), cell. Small molecules can easily Passive diffusion, diffuse through the pores. Nuclear transport includes the transportation of RNA and ribosomal proteins from the nucleus to the cytoplasm, and the transport of proteins (such as DNA polymerase and lamins), carbohydrates, signaling molecules, and lipids into the nucleus. Each nuclear pore complex can actively mediate up to 1000 translocations per second. The nuclear pore complex consists predominantly of a Protein family, family of proteins known as nucleoporins (Nups). Each pore complex in the human cell nucleus is composed of about 1,000 individual protein molecules, from an Conserved s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphoproteins
A phosphoprotein is a protein that is posttranslationally modified by the attachment of either a single phosphate group, or a complex molecule such as 5'-phospho-DNA, through a phosphate group. The target amino acid is most often serine, threonine, or tyrosine residues (mostly in eukaryotes), or aspartic acid or histidine residues (mostly in prokaryotes). Biological function The phosphorylation of proteins is a major regulatory mechanism in cells. Clinical significance Phosphoproteins have been proposed as biomarkers for breast cancer Breast cancer is a cancer that develops from breast tissue. Signs of breast cancer may include a Breast lump, lump in the breast, a change in breast shape, dimpling of the skin, Milk-rejection sign, milk rejection, fluid coming from the nipp .... See also * Protein phosphorylation * Phosphoserine References Phosphoproteins {{protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
