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MLN64
StAR related lipid transfer domain containing 3 (STARD3) is a protein that in humans is encoded by the STARD3 gene. STARD3 also known as metastatic lymph node 64 protein (MLN64) is a late endosomal integral membrane protein involved in cholesterol transport. STARD3 creates membrane contact sites between the endoplasmic reticulum (ER) and late endosomes where it moves cholesterol. Function This gene encodes a member of a subfamily of lipid trafficking proteins that are characterized by a C-terminal steroidogenic acute regulatory domain and an N-terminal metastatic lymph node 64 domain. The encoded protein localizes to the membranes of late endosomes and may be involved in exporting cholesterol. Alternative splicing results in multiple transcript variants. rovided by RefSeq, Oct 2009 STARD3 is involved in cholesterol transport from the ER to late endosomes where the protein is anchored. It forms a complex with fellow late endosomal protein STARD3 N-terminal-like protein ( STARD3N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STARD3NL
MENTHO or STARD3 N-terminal like protein (STARD3NL) is an integral membrane protein of unknown function. As the alternate name implies, MENTHO, short for "MLN64 N-terminal homologue", contains a region in its N-terminus similar to that found in STARD3, also known as MLN64, but lacks the StAR-related transfer domain (START) that characterizes all other proteins given the "STARD" (START domain-containing) name. The N-terminus, N-terminal domain is called a MENTAL domain, MENTAL (MLN64 N-terminal) domain. Like MLN64, MENTHO is widely expressed in tissues of the body. Within the Cell (biology), cell, it localizes to the membranes of endosome, late endosomes and may interact there with MLN64. It is suggested that in combination with MLN64, this protein helps regulate the flow of cholesterol through the endosomal pathway. References Further reading * * * * * * * * * * * External links * Integral membrane proteins {{gene-7-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MENTAL Domain
The MENTAL or MLN64 NH2-terminal domain is a membrane-spanning domain that is conserved in two late endosomal proteins in vertebrates, MLN64 and MENTHO. The domain is 170 amino acids long. Current data indicates that this domain allows for dimerization between MLN64 and MENTHO molecules and with themselves. The domain may also direct cholesterol Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ... transport. References {{reflist Protein domains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steroidogenic Acute Regulatory Protein
The steroidogenic acute regulatory protein, commonly referred to as StAR (STARD1), is a transport protein that regulates cholesterol transfer within the mitochondria, which is the rate-limiting step in the production of steroid hormones. It is primarily present in steroid-producing cells, including theca cells and luteal cells in the ovary, Leydig cells in the testis and cell types in the adrenal cortex. Function Cholesterol needs to be transferred from the outer mitochondrial membrane to the inner membrane where cytochrome P450scc enzyme (CYP11A1) cleaves the cholesterol side chain, which is the first enzymatic step in all steroid synthesis. The aqueous phase between these two membranes cannot be crossed by the lipophilic cholesterol, unless certain proteins assist in this process. A number of proteins have historically been proposed to facilitate this transfer including: sterol carrier protein 2 (SCP2), steroidogenic activator polypeptide (SAP), peripheral benzodiazepine recep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steroidogenic Acute Regulatory Protein
The steroidogenic acute regulatory protein, commonly referred to as StAR (STARD1), is a transport protein that regulates cholesterol transfer within the mitochondria, which is the rate-limiting step in the production of steroid hormones. It is primarily present in steroid-producing cells, including theca cells and luteal cells in the ovary, Leydig cells in the testis and cell types in the adrenal cortex. Function Cholesterol needs to be transferred from the outer mitochondrial membrane to the inner membrane where cytochrome P450scc enzyme (CYP11A1) cleaves the cholesterol side chain, which is the first enzymatic step in all steroid synthesis. The aqueous phase between these two membranes cannot be crossed by the lipophilic cholesterol, unless certain proteins assist in this process. A number of proteins have historically been proposed to facilitate this transfer including: sterol carrier protein 2 (SCP2), steroidogenic activator polypeptide (SAP), peripheral benzodiazepine recep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
StAR-related Transfer Domain
START (StAR-related lipid-transfer) is a lipid-binding domain in StAR, HD-ZIP and signalling proteins. The archetypical domain is found in StAR ( Steroidogenic acute regulatory protein), a mitochondrial protein that is synthesized in steroid-producing cells. StAR initiates steroid production by mediating the delivery of cholesterol to the first enzyme in steroidogenic pathway. The START domain is critical for this activity, perhaps through the binding of cholesterol. Following the discovery of StAR, 15 START-domain-containing proteins (termed STARD1 through STARD15) were subsequently identified in vertebrates as well as other that are related. Thousands of proteins containing at least one START domain have been determined in invertebrates, bacteria and plants to form a larger superfamily, variously known as START, Bet v1-like or SRPBCC (START/RHOalphaC/ PITP/Bet v1/CoxG/CalC) domain proteins, all of which bind hydrophobic ligands. In the case of plants, many of the START pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lutein
Lutein (;"Lutein" . from ''luteus'' meaning "yellow") is a and one of 600 known naturally occurring carotenoids. Lutein is synthesized only by plants, and like other xanthophylls is found in high quantities in [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malignant Tumors
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in bowel movements. While these symptoms may indicate cancer, they can also have other causes. Over 100 types of cancers affect humans. Tobacco use is the cause of about 22% of cancer deaths. Another 10% are due to obesity, poor diet, lack of physical activity or excessive drinking of alcohol. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. In the developing world, 15% of cancers are due to infections such as ''Helicobacter pylori'', hepatitis B, hepatitis C, human papillomavirus infection, Epstein–Barr virus and human immunodeficiency virus (HIV). These factors act, at least partly, by changing the genes of a cell. Ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a vertebrate's body. In a human, the cerebral cortex contains approximately 14–16 billion neurons, and the estimated number of neurons in the cerebellum is 55–70 billion. Each neuron is connected by synapses to several thousand other neurons. These neurons typically communicate with one another by means of long fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells. Physiologically, brains exert centralized control over a body's other organs. They act on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows rapid and coordinated respon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray Crystallography
X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information. Since many materials can form crystals—such as salts, metals, minerals, semiconductors, as well as various inorganic, organic, and biological molecules—X-ray crystallography has been fundamental in the development of many scientific fields. In its first decades of use, this method determined the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences among various mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homology (chemistry)
In chemistry, homology is the appearance of homologues. A homologue (also spelled as homolog) is a compound belonging to a series of compounds differing from each other by a repeating unit, such as a methylene bridge −−, a peptide residue, etc. A homolog is a special case of an analog. Examples are alkanes and compounds with alkyl side chains of different length (the repeating unit being a methylene group -CH2-). Periodic table On the periodic table, homologous elements share many electrochemical properties and appear in the same group (column) of the table. For example, all noble gases are colorless, monatomic gases with very low reactivity. These similarities are due to similar structure in their outer shells of valence electrons. Mendeleev used the prefix eka- for an unknown element below a known one in the same group. See also * Homologous series * Analog Analog or analogue may refer to: Computing and electronics * Analog signal, in which information is enco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorylation
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
