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Magnesium Transporter1 Family
The Magnesium Transporter 1 (MagT1) FamilyTC# 1.A.76 is a group of magnesium transporters that are part of the TOG superfamily. Goytain and Quamme identified a Mg2+-related transporter whose expression or function was affected by an implantation-associated protein precursor. They designated this protein, MagT1. MagT1 is expressed as a 335 amino acid polypeptide which includes five transmembrane helices. The nascent polypeptide possesses a cleavage site after the N-terminal signal sequence helix, rendering a mature MagT1 protein with four transmembrane helices. MagT1 additionally contains a number of phosphorylation sites. Recent evidence demonstrates that the primary function of MagT1 is protein glycosylation, mediated by MagT1's function as a component of the oligosaccharyltransferase (OST). Function When expressed in ''Xenopus laevis'' oocytes, MagT1 mediates saturable Mg2+ uptake with a Km of 0.23 mM. Transport of Mg2+ by MagT1 is rheogenic, voltage-dependent, and does not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TOG Superfamily
The transporter-opsin-G protein-coupled receptor (TOG) superfamily is a protein superfamily of integral membrane proteins, usually of 7 or 8 transmembrane alpha-helical segments (TMSs). It includes (1) ion-translocating microbial rhodopsins and (2) G protein-coupled receptors (GPCRs), (3) Sweet sugar transporters, (4) nicotinamide ribonucleoside uptake permeases (PnuCTC# 4.B.1, (5) 4-toluene sulfonate uptake permeases (TSUP)TC# 2.A.102, (6) Ni2+–Co2+ transporters (NiCoT)TC# 2.A.52, (7) organic solute transporters (OST)TC# 2.A.82, (8) phosphate:Na+ symporters (PNaS)TC# 2.A.58 and (9) lysosomal cystine transporters (LCT)TC# 2.A.43. Families Currently recognized families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ... within the TOG Superfamily (with TC numbers in blue) inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epstein–Barr Virus
The Epstein–Barr virus (EBV), formally called ''Human gammaherpesvirus 4'', is one of the nine known human herpesvirus types in the herpes family, and is one of the most common viruses in humans. EBV is a double-stranded DNA virus. It is best known as the cause of infectious mononucleosis ("mono" or "glandular fever"). It is also associated with various non-malignant, premalignant, and malignant Epstein–Barr virus-associated lymphoproliferative diseases such as Burkitt lymphoma, hemophagocytic lymphohistiocytosis, and Hodgkin's lymphoma; non-lymphoid malignancies such as gastric cancer and nasopharyngeal carcinoma; and conditions associated with human immunodeficiency virus such as hairy leukoplakia and central nervous system lymphomas. The virus is also associated with the childhood disorders of Alice in Wonderland syndrome and acute cerebellar ataxia and, by some evidence, higher risks of developing certain autoimmune diseases, especially dermatomyositis, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmembrane Transporters
A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequently undergo significant conformational changes to move a substance through the membrane. They are usually highly hydrophobic and aggregate and precipitate in water. They require detergents or nonpolar solvents for extraction, although some of them (beta-barrels) can be also extracted using denaturing agents. The peptide sequence that spans the membrane, or the transmembrane segment, is largely hydrophobic and can be visualized using the hydropathy plot. Depending on the number of transmembrane segments, transmembrane proteins can be classified as single-span (or bitopic) or multi-span (polytopic). Some other integral membrane proteins are called monotopic, meaning that they are also permanently attached to the membrane, but do not pas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Proteins
Membrane proteins are common proteins that are part of, or interact with, biological membranes. Membrane proteins fall into several broad categories depending on their location. Integral membrane proteins are a permanent part of a cell membrane and can either penetrate the membrane ( transmembrane) or associate with one or the other side of a membrane ( integral monotopic). Peripheral membrane proteins are transiently associated with the cell membrane. Membrane proteins are common, and medically important—about a third of all human proteins are membrane proteins, and these are targets for more than half of all drugs. Nonetheless, compared to other classes of proteins, determining membrane protein structures remains a challenge in large part due to the difficulty in establishing experimental conditions that can preserve the correct conformation of the protein in isolation from its native environment. Function Membrane proteins perform a variety of functions vital to the su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Families
A protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be confused with family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar three-dimensional structures, functions, and significant sequence similarity. The most important of these is sequence similarity (usually amino-acid sequence), since it is the strictest indicator of homology and therefore the clearest indicator of common ancestry. A fairly well developed framework exists for evaluating the significance of similarity between a group of sequences using sequence alignment methods. Proteins that do not share a common ancestor are very unlikely to show statistically significant sequence similarity, making sequence alignment a powerful tool for identifying the members of protein famil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATR-X Syndrome
Alpha-thalassemia mental retardation syndrome (ATRX), also called alpha-thalassemia X-linked intellectual disability syndrome, nondeletion type or ATR-X syndrome, is an X-linked recessive condition associated with a mutation in the '' ATRX'' gene. Males with this condition tend to be moderately intellectually disabled and have physical characteristics including coarse facial features, microcephaly (small head size), hypertelorism (widely spaced eyes), a depressed nasal bridge, a tented upper lip and an everted lower lip. Mild or moderate anemia, associated with alpha-thalassemia, is part of the condition. Females with this mutated gene have no specific signs or features, but if they do, they may demonstrate skewed X chromosome inactivation. Atr-X Syndrome can also come with problems regulating Levels and normal bodily temperature regulation, the cause of this is widely debated but currently unknown, many children with Atr-X may need oxygen support long term through their entire l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoplasm
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, when it may be called a tumor. ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word is from Ancient Greek 'new' and 'formation, creation'. Types A neoplasm can be benign, potentia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XMEN Disease
XMEN disease is a rare genetic disorder of the immune system that illustrates the role of glycosylation in the function of the immune system. XMEN stands for “X-linked MAGT1 deficiency with increased susceptibility to Epstein–Barr virus (EBV) infection and N-linked glycosylation defect.” The disease is characterized by CD4 lymphopenia, severe chronic viral infections, and defective T-lymphocyte activation. Investigators in the laboratory of Dr. Michael Lenardo, National Institute of Allergy and Infectious Diseases at the National Institutes of Health first described this condition in 2011. Presentation XMEN patients have splenomegaly, chronic Epstein Barr Virus (EBV) infection, and are developmentally normal. They have an increased susceptibility for developing EBV+ lymphoma. Additionally, XMEN patients have excessive infections consistent with the underlying immunodeficiency. These infections included recurrent otitis media, sinusitis, viral pneumonia, diarrhea, upp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligosaccharyltransferase
Oligosaccharyltransferase or OST () is a membrane protein complex that transfers a 14- sugar oligosaccharide from dolichol to nascent protein. It is a type of glycosyltransferase. The sugar Glc3Man9GlcNAc2 (where Glc=Glucose, Man=Mannose, and GlcNAc= ''N''-acetylglucosamine) is attached to an asparagine (Asn) residue in the sequence Asn-X-Ser or Asn-X- Thr where X is any amino acid except proline. This sequence is called a glycosylation ''sequon.'' The reaction catalyzed by OST is the central step in the ''N''-linked glycosylation pathway. Location OST is a component of the translocon in the endoplasmic reticulum (ER) membrane. A lipid-linked core-oligosaccharide is assembled at the membrane of the endoplasmic reticulum and transferred to selected asparagine residues of nascent polypeptide chains by the oligosaccharyl transferase complex. The active site of OST is located about 4 nm from the lumenal face of the ER membrane. It usually acts during translation as the nasc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-cell Mediated Immunity
Cell-mediated immunity or cellular immunity is an immune response that does not involve antibodies. Rather, cell-mediated immunity is the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen. History In the late 19th century Hippocratic tradition medicine system, the immune system was imagined into two branches: humoral immunity, for which the protective function of immunization could be found in the humor (cell-free bodily fluid or serum) and cellular immunity, for which the protective function of immunization was associated with cells. CD4 cells or helper T cells provide protection against different pathogens. Naive T cells, which are immature T cells that have yet to encounter an antigen, are converted into activated effector T cells after encountering antigen-presenting cells (APCs). These APCs, such as macrophages, dendritic cells, and B cells in some circumstances, load antigenic peptides onto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Messenger RNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the process of transcription, where an enzyme (RNA polymerase) converts the gene into primary transcript mRNA (also known as pre-mRNA). This pre-mRNA usually still contains introns, regions that will not go on to code for the final amino acid sequence. These are removed in the process of RNA splicing, leaving only exons, regions that will encode the protein. This exon sequence constitutes mature mRNA. Mature mRNA is then read by the ribosome, and, utilising amino acids carried by transfer RNA (tRNA), the ribosome creates the protein. This process is known as translation. All of these processes form part of the central dogma of molecular biology, which describes the flow of genetic information in a biological system. As in DNA, genet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
