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Hnf4
HNF4 (Hepatocyte Nuclear Factor 4) is a nuclear receptor protein mostly expressed in the liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ..., gut, kidney, and pancreatic beta cells that is critical for liver development. In humans, there are two paralogs of HNF4, HNF4α and HNF4γ, encoded by two separate genes and respectively. Ligands HNF4 was originally classified as an orphan receptor that exhibits constitutive transactivation activity apparently by being continuously bound to a variety of fatty acids. The existence of a ligand for HNF4 has been somewhat controversial, but linoleic acid (LA) has been identified as the endogenous ligand of native HNF4 expressed in mouse liver; the binding of LA to HNF4 is reversible. The ligand binding domain of HNF4, as with othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Receptor
In the field of molecular biology, nuclear receptors are a class of proteins responsible for sensing steroids, thyroid hormones, vitamins, and certain other molecules. These intracellular receptors work with other proteins to regulate the expression of specific genes, thereby controlling the development, homeostasis, and metabolism of the organism. Nuclear receptors bind directly to DNA regulating the expression of adjacent genes; hence these receptors are classified as transcription factors. The regulation of gene expression by nuclear receptors often occurs in the presence of a ligand—a molecule that affects the receptor's behavior. Ligand binding to a nuclear receptor results in a conformational change activating the receptor. The result is up- or down-regulation of gene expression. A unique property of nuclear receptors that differentiates them from other classes of receptors is their direct control of genomic DNA. Nuclear receptors play key roles in both embryonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HNF4G (gene)
__NOTOC__ Hepatocyte nuclear factor 4 gamma (HNF4G) also known as NR2A2 (nuclear receptor subfamily 2, group A, member 2) is a nuclear receptor that in humans is encoded by the ''HNF4G'' ''gene''. Function HNF4G is a transcription factor that has been shown to play a significant role in intestinal epithelial cell differentiation and function. Research using integrative multi-omics analysis of intestinal organoid differentiation has revealed that HNF4G acts as a master regulator of gene regulation in differentiation towards the enterocyte lineage. The study demonstrated widespread binding to promoters and enhancers that are activated in enterocytes, and that the loss of Hnf4g results in a partial loss of enterocyte differentiation, indicating its importance in maintaining the enterocyte lineage. See also *Hepatocyte nuclear factor 4 *Hepatocyte nuclear factors Hepatocyte nuclear factors (HNFs) are a group of phylogenetically unrelated transcription factors that regulate the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatocyte Nuclear Factor 4 Gamma
__NOTOC__ Hepatocyte nuclear factor 4 gamma (HNF4G) also known as NR2A2 (nuclear receptor subfamily 2, group A, member 2) is a nuclear receptor In the field of molecular biology, nuclear receptors are a class of proteins responsible for sensing steroids, thyroid hormones, vitamins, and certain other molecules. These intracellular receptors work with other proteins to regulate the ex ... that in humans is encoded by the ''HNF4G'' ''gene''. Function HNF4G is a transcription factor that has been shown to play a significant role in intestinal epithelial cell differentiation and function. Research using integrative multi-omics analysis of intestinal organoid differentiation has revealed that HNF4G acts as a master regulator of gene regulation in differentiation towards the enterocyte lineage. The study demonstrated widespread binding to promoters and enhancers that are activated in enterocytes, and that the loss of Hnf4g results in a partial loss of enterocyte differentiation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatocyte Nuclear Factor 4 Alpha
Hepatocyte nuclear factor 4 alpha (HNF4A) also known as NR2A1 (nuclear receptor subfamily 2, group A, member 1) is a nuclear receptor that in humans is encoded by the ''HNF4A'' gene. Function HNF-4α is a nuclear transcription factor that binds DNA as a homodimer. The encoded protein controls the expression of several genes, including hepatocyte nuclear factor 1 alpha, a transcription factor that regulates the expression of several hepatic genes. This gene plays a role in development of the liver, kidney, and intestines. Alternative splicing of this gene results in multiple transcript variants. HNF4A is required for the PXR and CAR-mediated transcriptional activation of CYP3A4. Genetic mutations in the ''HNF4A'' gene can influence the activity of HNF4α's downstream proteins such as CYP2D6, ''in vitro'' and ''in vivo''. The alkaloid berberine upregulates HNF4A expression. This gene plays a pivotal role in the expression and synthesis of SHBG, an important glycoprotein mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coactivation (Transcription)
A coactivator is a type of transcriptional coregulator that binds to an activator (a transcription factor) to increase the rate of transcription of a gene or set of genes. The activator contains a DNA binding domain that binds either to a DNA promoter site or a specific DNA regulatory sequence called an enhancer. Binding of the activator-coactivator complex increases the speed of transcription by recruiting general transcription machinery to the promoter, therefore increasing gene expression. The use of activators and coactivators allows for highly specific expression of certain genes depending on cell type and developmental stage. Some coactivators also have histone acetyltransferase (HAT) activity. HATs form large multiprotein complexes that weaken the association of histones to DNA by acetylating the N-terminal histone tail. This provides more space for the transcription machinery to bind to the promoter, therefore increasing gene expression. Activators are found in all ... [...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 funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulin Resistance
Insulin resistance (IR) is a pathological response in which cells in insulin-sensitive tissues in the body fail to respond normally to the hormone insulin or downregulate insulin receptors in response to hyperinsulinemia. Insulin is a hormone that facilitates the transport of glucose from blood into cells, thereby reducing blood glucose (blood sugar). Insulin is released by the pancreas in response to carbohydrates consumed in the diet. In states of insulin resistance, the same amount of insulin does not have the same effect on glucose transport and blood sugar levels. There are many causes of insulin resistance and the underlying process is still not completely understood. Risk factors for insulin resistance include obesity, sedentary lifestyle, family history of diabetes, various health conditions, and certain medications. Insulin resistance is considered a component of the metabolic syndrome. Insulin resistance can be improved or reversed with lifestyle approaches, such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SHBG
Sex hormone-binding globulin (SHBG) or sex steroid-binding globulin (SSBG) is a glycoprotein that binds to androgens and estrogens. When produced by the Sertoli cells in the seminiferous tubules of the testis, it is called androgen-binding protein (ABP). Other steroid hormones such as progesterone, cortisol, and other corticosteroids are bound by transcortin. SHBG is found in all vertebrates apart from birds. Function Testosterone and estradiol circulate in the bloodstream, loosely bound mostly to serum albumin (~54%), and to a lesser extent bound tightly to SHBG (~44%). Only a very small fraction of about 1 to 2% is unbound, or "free," and thus biologically active and able to enter a cell and activate its receptor. SHBG inhibits the function of these hormones. Thus, the local bioavailability of sex hormones is influenced by the level of SHBG. Because SHBG binds to testosterone (T) and dihydrotestosterone (DHT), these hormones are made less lipophilic and become concentrated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MODY 1
MODY 1 or HNF4A-MODY is a form of maturity onset diabetes of the young. MODY 1 is due to a loss-of-function mutation in the '' HNF4A'' (''MODY1'') gene on chromosome 12. This gene codes for hepatocyte nuclear factor 4-alpha (HNF4-α) protein also known as transcription factor 14 (TCF14). HNF4α controls function of HNF1α (see MODY 3; ) and perhaps HNF1β ( MODY 5) as well. This transcription network plays a role in the early development of the pancreas, liver, and intestines. In the pancreas these genes influence expression of, among others, the genes for insulin, the principal glucose transporter (GLUT2), and several proteins involved in glucose and mitochondrial metabolism. Although pancreatic beta cells produce adequate insulin in infancy, the capacity for insulin production declines thereafter. Diabetes (persistent hyperglycemia) typically develops by early adult years, but may not appear until later decades. The degree of insulin deficiency is slowly progressive. Many pat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orphan Receptor
In biochemistry, an orphan receptor is a protein that has a similar structure to other identified receptors but whose endogenous ligand has not yet been identified. If a ligand for an orphan receptor is later discovered, the receptor is referred to as an "adopted orphan". Conversely, the term orphan ligand refers to a biological ligand whose cognate receptor has not yet been identified. Examples Examples of orphan receptors are found in the G protein-coupled receptor (GPCR) and nuclear receptor families. If an endogenous ligand is found, the orphan receptor is "adopted" or "de-orphanized". An example is the nuclear receptor farnesoid X receptor (FXR) and TGR5/GPCR19/G protein-coupled bile acid receptor, both of which are activated by bile acids. Adopted orphan receptors in the nuclear receptor group include FXR, liver X receptor (LXR), and peroxisome proliferator-activated receptor (PPAR). Another example of an orphan receptor site is the PCP binding site in the NMDA recep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Domains
In molecular biology, a protein domain is a region of a protein's polypeptide chain that is self-stabilizing and that folds independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist of several domains, and a domain may appear in a variety of different proteins. Molecular evolution uses domains as building blocks and these may be recombined in different arrangements to create proteins with different functions. In general, domains vary in length from between about 50 amino acids up to 250 amino acids in length. The shortest domains, such as zinc fingers, are stabilized by metal ions or disulfide bridges. Domains often form functional units, such as the calcium-binding EF hand domain of calmodulin. Because they are independently stable, domains can be "swapped" by genetic engineering between one protein and another to make chimeric proteins. Background The concept of the domain was first proposed in 1973 by Wetlaufer after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linoleic Acid
Linoleic acid (LA) is an organic compound with the formula . Both alkene groups () are ''cis''. It is a fatty acid sometimes denoted 18:2 (n−6) or 18:2 ''cis''-9,12. A linoleate is a salt or ester of this acid. Linoleic acid is a polyunsaturated, omega−6 fatty acid. It is a colorless liquid that is virtually insoluble in water but soluble in many organic solvents. It typically occurs in nature as a triglyceride (ester of glycerin) rather than as a free fatty acid. It is one of two essential fatty acids for humans, who must obtain it through their diet, and the most essential, because the body uses it as a base to make the others. The word "linoleic" derives , reflecting the fact that it was first isolated from linseed oil. History In 1844, F. Sacc, working at the laboratory of Justus von Liebig Justus ''Freiherr'' von Liebig (12 May 1803 – 18 April 1873) was a Germans, German scientist who made major contributions to the theory, practice, and pedagogy of che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
