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FOXA1
Forkhead box protein A1 (FOXA1), also known as hepatocyte nuclear factor 3-alpha (HNF-3A), is a protein that in humans is encoded by the ''FOXA1'' gene. Function FOXA1 is a member of the forkhead class of DNA-binding proteins. These hepatocyte nuclear factors are transcriptional activators for liver-specific transcripts such as albumin and transthyretin, and they also interact with chromatin as a pioneer factor. Similar family members in mice have roles in the regulation of metabolism and in the differentiation of the pancreas and liver. Marker in breast cancer FOXA1 in breast cancer is highly correlated with ERα+, GATA3+, and PR+ protein expression as well as endocrine signaling. FOXA1 acts as a pioneer factor for ERa in ERα+ breast cancer, and its expression might identify ERα+ cancers that undergo rapid reprogramming of ERa signaling that is associated with poor outcomes and treatment resistance. Conversely, in ERα− breast cancer FOXA1 is highly correlated with lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatocyte Nuclear Factors
Hepatocyte nuclear factors (HNFs) are a group of phylogenetically unrelated transcription factors that regulate the transcription of a diverse group of genes into proteins. These proteins include blood clotting factors and in addition, enzymes and transporters involved with glucose, cholesterol, and fatty acid transport and metabolism. Function As the name suggests, hepatocyte nuclear factors are expressed predominantly in the liver. However HNFs are also expressed and play important roles in a number of other tissues so that the name ''hepatocyte nuclear factor'' is somewhat misleading. Nevertheless, the liver is the only tissue in which a significant number of different HNFs are expressed at the same time. In addition, there are a number of genes which contain multiple promoter and enhancer regions each regulated by a different HNF. Furthermore, efficient expression of these genes require synergistic activation by multiple HNFs. Hence hepatocyte nuclear factors functio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pioneer Factor
Pioneer factors are transcription factors that can directly bind condensed chromatin. They can have positive and negative effects on transcription and are important in recruiting other transcription factors and histone modification enzymes as well as controlling DNA methylation. They were first discovered in 2002 as factors capable of binding to target sites on nucleosomal DNA in compacted chromatin and endowing competency for gene activity during hepatogenesis. Pioneer factors are involved in initiating cell differentiation and activation of cell-specific genes. This property is observed in histone fold-domain containing transcription factors (fork head box (FOX) and NF-Y) and other transcription factors that use zinc finger(s) for DNA binding (Groucho TLE, Gal4, and GATA). The eukaryotic cell condenses its genome into tightly packed chromatin and nucleosomes. This ability saves space in the nucleus for only actively transcribed genes and hides unnecessary or detrimental gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GATA3
GATA3 is a transcription factor that in humans is encoded by the ''GATA3'' gene. Studies in animal models and humans indicate that it controls the expression of a wide range of biologically and clinically important genes. The GATA3 transcription factor is critical for the embryonic development of various tissues as well as for inflammatory and humoral immune responses and the proper functioning of the endothelium of blood vessels. GATA3 plays central role in allergy and immunity against worm infections. ''GATA3'' haploinsufficiency (i.e. loss of one or the two inherited ''GATA3'' genes) results in a congenital disorder termed the Barakat syndrome. Current clinical and laboratory research is focusing on determining the benefits of directly or indirectly blocking the action of GATA3 in inflammatory and allergic diseases such as asthma. It is also proposed to be a clinically important marker for various types of cancer, particularly those of the breast. However, the role, if any, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FOX Proteins
FOX (forkhead box) proteins are a family of transcription factors that play important roles in regulating the expression of genes involved in cell growth, proliferation, differentiation, and longevity. Many FOX proteins are important to embryonic development. FOX proteins also have pioneering transcription activity by being able to bind condensed chromatin during cell differentiation processes. The defining feature of FOX proteins is the forkhead box, a sequence of 80 to 100 amino acids forming a motif that binds to DNA. This forkhead motif is also known as the winged helix, due to the butterfly-like appearance of the loops in the protein structure of the domain. Forkhead proteins are a subgroup of the helix-turn-helix class of proteins. Biological roles Many genes encoding FOX proteins have been identified. For example, the FOXF2 gene encodes forkhead box F2, one of many human homologues of the ''Drosophila melanogaster'' transcription factor forkhead. FOXF2 is expressed in t ... [...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] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albumin
Albumin is a family of globular proteins, the most common of which are the serum albumins. All the proteins of the albumin family are water-soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Albumins are commonly found in blood plasma and differ from other blood proteins in that they are not glycosylated. Substances containing albumins are called ''albuminoids''. A number of blood transport proteins are evolutionarily related in the albumin family, including serum albumin, alpha-fetoprotein, vitamin D-binding protein and afamin. This family is only found in vertebrates. ''Albumins'' in a less strict sense can mean other proteins that coagulate under certain conditions. See for lactalbumin, ovalbumin and plant "2S albumin". Function Albumins in general are transport proteins that bind to various ligands and carry them around. Human types include: * Human serum albumin is the main protein of human blood plasma. It makes up around 50 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transthyretin
Transthyretin (TTR or TBPA) is a transport protein in the plasma and cerebrospinal fluid that transports the thyroid hormone thyroxine (T4) and retinol to the liver. This is how transthyretin gained its name: ''transports thyroxine and retinol''. The liver secretes TTR into the blood, and the choroid plexus secretes TTR into the cerebrospinal fluid. TTR was originally called prealbumin (or thyroxine-binding prealbumin) because it migrated faster than albumin on electrophoresis gels. Prealbumin was felt to be a misleading name, it is not a synthetic precursor of albumin. The alternative name TTR was proposed by DeWitt Goodman in 1981. Transthyretin protein is encoded by the ''TTR'' gene located on the 18th chromosome. Binding affinities It functions in concert with two other thyroid hormone-binding proteins in the serum: In cerebrospinal fluid TTR is the primary carrier of T4. TTR also acts as a carrier of retinol (vitamin A) through its association with retinol-binding pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatin
Chromatin is a complex of DNA and protein found in eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important roles in reinforcing the DNA during cell division, preventing DNA damage, and regulating gene expression and DNA replication. During mitosis and meiosis, chromatin facilitates proper segregation of the chromosomes in anaphase; the characteristic shapes of chromosomes visible during this stage are the result of DNA being coiled into highly condensed chromatin. The primary protein components of chromatin are histones. An octamer of two sets of four histone cores (Histone H2A, Histone H2B, Histone H3, and Histone H4) bind to DNA and function as "anchors" around which the strands are wound.Maeshima, K., Ide, S., & Babokhov, M. (2019). Dynamic chromatin organization without the 30-nm fiber. ''Current opinion in cell biology, 58,'' 95–104. https://doi.o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breast Cancer
Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a red or scaly patch of skin. In those with distant spread of the disease, there may be bone pain, swollen lymph nodes, shortness of breath, or yellow skin. Risk factors for developing breast cancer include obesity, a lack of physical exercise, alcoholism, hormone replacement therapy during menopause, ionizing radiation, an early age at first menstruation, having children late in life or not at all, older age, having a prior history of breast cancer, and a family history of breast cancer. About 5–10% of cases are the result of a genetic predisposition inherited from a person's parents, including BRCA1 and BRCA2 among others. Breast cancer most commonly develops in cells from the lining of milk ducts and the lobules that supply these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estrogen Receptor Alpha
Estrogen receptor alpha (ERα), also known as NR3A1 (nuclear receptor subfamily 3, group A, member 1), is one of two main types of estrogen receptor, a nuclear receptor (mainly found as a chromatin-binding protein) that is activated by the sex hormone estrogen. In humans, ERα is encoded by the gene ''ESR1'' (EStrogen Receptor 1). Structure The estrogen receptor (ER) is a ligand-activated transcription factor composed of several domains important for hormone binding, DNA binding, and activation of transcription. Alternative splicing results in several ESR1 mRNA transcripts, which differ primarily in their 5-prime untranslated regions. The translated receptors show less variability. Ligands Agonists Non-selective * Endogenous estrogens (e.g., estradiol, estrone, estriol, estetrol) * Natural estrogens (e.g., conjugated equine estrogens) * Synthetic estrogens (e.g., ethinylestradiol, diethylstilbestrol) Selective Agonists of ERα selective over ERβ include: * Propylp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progesterone Receptor
The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone. In humans, PR is encoded by a single ''PGR'' gene residing on chromosome 11q22, it has two isoforms, PR-A and PR-B, that differ in their molecular weight. The PR-B is the positive regulator of the effects of progesterone, while PR-A serve to antagonize the effects of PR-B. Mechanism Progesterone is necessary to induce the progesterone receptors. When no binding hormone is present the carboxyl terminal inhibits transcription. Binding to a hormone induces a structural change that removes the inhibitory action. Progesterone antagonists prevent the structural reconfiguration. After progesterone binds to the receptor, restructuring with dimerization follows and the complex enters the nucleus and binds to DNA. There transcription takes place, resulting in formation of messenger RNA that is tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
