|
Hormone Response Element
''Response elements'' are short sequences of DNA within a gene promoter or enhancer region that are able to bind specific transcription factors and regulate transcription of genes. Under conditions of stress, a transcription activator protein binds to the response element and stimulates transcription. If the same response element sequence is located in the control regions of different genes, then these genes will be activated by the same stimuli, thus producing a coordinated response. Hormone response element A hormone response element (HRE) is a short sequence of DNA within the promoter of a gene, that is able to bind to a specific hormone receptor complex and therefore regulate transcription. The sequence is most commonly a pair of inverted repeats separated by three nucleotides, which also indicates that the receptor binds as a dimer. Specifically, HRE responds to steroid hormones, as the activated steroid receptor is the transcription factor binding HRE. This regulates the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Promoter (genetics)
In genetics, a promoter is a sequence of DNA to which proteins bind to initiate transcription of a single RNA transcript from the DNA downstream of the promoter. The RNA transcript may encode a protein (mRNA), or can have a function in and of itself, such as tRNA or rRNA. Promoters are located near the transcription start sites of genes, upstream on the DNA (towards the 5' region of the sense strand). Promoters can be about 100–1000 base pairs long, the sequence of which is highly dependent on the gene and product of transcription, type or class of RNA polymerase recruited to the site, and species of organism. Overview For transcription to take place, the enzyme that synthesizes RNA, known as RNA polymerase, must attach to the DNA near a gene. Promoters contain specific DNA sequences such as response elements that provide a secure initial binding site for RNA polymerase and for proteins called transcription factors that recruit RNA polymerase. These transcription factor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxisome Proliferator-activated Receptor
In the field of molecular biology, the peroxisome proliferator–activated receptors (PPARs) are a group of nuclear receptor proteins that function as transcription factors regulating gene expression. PPARs play essential roles in regulating cell differentiation, cellular differentiation, developmental biology, development, and metabolism (carbohydrate metabolism, carbohydrate, lipid metabolism, lipid, protein metabolism, protein), and tumorigenesis Nomenclature and tissue distribution Three types of PPARs have been identified: alpha, PPARG, gamma, and delta (beta): * Peroxisome proliferator-activated receptor alpha, α (alpha) - expressed in liver, kidney, heart, muscle, adipose tissue, and others * Peroxisome proliferator-activated receptor delta, β/δ (beta/delta) - expressed in many tissues, especially in brain, adipose tissue, and skin * Peroxisome proliferator-activated receptor gamma, γ (gamma) - although transcribed by the same gene, this PPAR, by way of alternativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HIV Rev Response Element
The HIV-1 Rev response element (RRE) is a highly structured, ~350 nucleotide RNA segment present in the Env coding region of unspliced and partially spliced viral mRNAs. In the presence of the HIV-1 accessory protein Rev, HIV-1 m RNAs that contain the RRE can be exported from the nucleus to the cytoplasm for downstream events such as translation and virion packaging. RRE and HIV-1 biology Early phase The HIV-1 genome contains a single promoter and uses multiple reading frames and alternative splicing to encode 15 proteins from a single pre-mRNA species. Transcription from an integrated HIV-1 provirus generates a single 9 kilobase (kb) pre-mRNA containing multiple splice sites and nuclear retention signals. In the early phase of the viral life cycle, this pre-RNA is completely spliced to RRE-free, 2 kb messages. These smaller messages are then transported from the nucleus to the cytoplasm via standard mRNA nuclear export pathways (see Figure). One of these small, 2kb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycomb-group Proteins
Polycomb-group proteins (PcG proteins) are a family of protein complexes first discovered in fruit flies that can remodel chromatin such that epigenetic silencing of genes takes place. Polycomb-group proteins are well known for silencing Hox genes through modulation of chromatin structure during embryonic development in fruit flies (''Drosophila melanogaster''). They derive their name from the fact that the first sign of a decrease in PcG function is often a homeotic transformation of posterior legs towards anterior legs, which have a characteristic comb-like set of bristles. In insects In ''Drosophila'', the Trithorax-group (trxG) and Polycomb-group (PcG) proteins act antagonistically and interact with chromosomal elements, termed Cellular Memory Modules (CMMs). Trithorax-group (trxG) proteins maintain the active state of gene expression while the Polycomb-group (PcG) proteins counteract this activation with a repressive function that is stable over many cell generations and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterol Regulatory Element-binding Protein
Sterol regulatory element-binding proteins (SREBPs) are transcription factors that bind to the sterol regulatory element DNA sequence TCACNCCAC. Mammalian SREBPs are encoded by the genes ''SREBF1'' and ''SREBF2''. SREBPs belong to the basic-helix-loop-helix leucine zipper class of transcription factors. Unactivated SREBPs are attached to the nuclear envelope and endoplasmic reticulum membranes. In cells with low levels of sterols, SREBPs are cleaved to a water-soluble N-terminal domain that is translocated to the nucleus. These activated SREBPs then bind to specific sterol regulatory element DNA sequences, thus upregulating the synthesis of enzymes involved in sterol biosynthesis. Sterols in turn inhibit the cleavage of SREBPs and therefore synthesis of additional sterols is reduced through a negative feed back loop. Isoforms Mammalian genomes have two separate SREBP genes ( and ): * SREBP-1 expression produces two different isoforms, SREBP-1a and -1c. These isoforms differ in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NFE2L2
Nuclear factor erythroid 2-related factor 2 (NRF2), also known as nuclear factor erythroid-derived 2-like 2, is a transcription factor that in humans is encoded by the ''NFE2L2'' gene. NRF2 is a bZIP domain, basic leucine zipper (bZIP) protein that may regulate the expression of antioxidant proteins that protect against oxidative stress, oxidative damage triggered by injury and inflammation, according to preliminary research. ''In vitro'', NRF2 binds to antioxidant response elements (AREs) in the promoter regions of genes encoding antioxidant, cytoprotective proteins. NRF2 induces the expression of Heme oxygenase#Heme oxygenase 1, heme oxygenase 1 ''in vitro'' leading to an increase in Drug metabolism#Phase II – conjugation, phase II enzymes. NRF2 also inhibits the NLRP3 inflammasome. NRF2 appears to participate in a complex regulatory network and performs a pleiotropic role in the regulation of metabolism, inflammation, autophagy, proteostasis, mitochondrial physiology, and i ... [...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] |
MTF1
Metal regulatory transcription factor 1 is a protein that in humans is encoded by the ''MTF1'' gene. Function This gene encodes a transcription factor that induces expression of metallothionein Metallothionein (MT) is a family of cysteine-rich, low molecular weight (MW ranging from 500 to 14000 Da) proteins. They are localized to the membrane of the Golgi apparatus. MTs have the capacity to bind both physiological (such as zinc, copp ...s and other genes involved in metal homeostasis in response to heavy metals such as cadmium, zinc, copper, and silver. The protein is a nucleocytoplasmic shuttling protein that accumulates in the nucleus upon heavy metal exposure and binds to promoters containing a metal-responsive element (MRE). References Further reading * * * * * * * * * * * * * External links * {{Transcription factors, g2 Transcription factors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serum Response Factor
Serum response factor, also known as SRF, is a transcription factor protein. Function Serum response factor is a member of the MADS (MCM1, Agamous, Deficiens, and SRF) box superfamily of transcription factors. This protein binds to the serum response element (SRE) in the promoter region of target genes. This protein regulates the activity of many immediate early genes, for example c-fos, and thereby participates in cell cycle regulation, apoptosis, cell growth, and cell differentiation. This gene is the downstream target of many pathways; for example, the mitogen-activated protein kinase pathway (MAPK) that acts through the ternary complex factors (TCFs). SRF is important during the development of the embryo, as it has been linked to the formation of mesoderm. In the fully developed mammal, SRF is crucial for the growth of skeletal muscle. Interaction of SRF with other proteins, such as steroid hormone receptors, may contribute to regulation of muscle growth by steroids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoxia-inducible Factor
Hypoxia-inducible factors (HIFs) are transcription factors that respond to decreases in available oxygen in the cellular environment, or hypoxia. They also respond to instances of pseudohypoxia, such as thiamine deficiency. Both hypoxia and pseudohypoxia leads to impairment of adenosine triphosphate (ATP) production by the mitochondria. Discovery The HIF transcriptional complex was discovered in 1995 by Gregg L. Semenza and postdoctoral fellow Guang Wang. In 2016, William Kaelin Jr., Peter J. Ratcliffe and Gregg L. Semenza were presented the Lasker Award for their work in elucidating the role of HIF-1 in oxygen sensing and its role in surviving low oxygen conditions. In 2019, the same three individuals were jointly awarded the Nobel Prize in Physiology or Medicine for their work in elucidating how HIF senses and adapts cellular response to oxygen availability. Structure Oxygen-breathing species express the highly conserved transcriptional complex HIF-1, which is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aryl Hydrocarbon Receptor
The aryl hydrocarbon receptor (also known as AhR, AHR, ahr, ahR, AH receptor, or as the dioxin receptor) is a protein that in humans is encoded by the AHR gene. The aryl hydrocarbon receptor is a transcription factor that regulates gene expression. It was originally thought to function primarily as a sensor of xenobiotic chemicals and also as the regulator of enzymes such as cytochrome P450s that metabolize these chemicals. The most notable of these xenobiotic chemicals are aromatic (aryl) hydrocarbons from which the receptor derives its name. More recently, it has been discovered that AhR is activated (or deactivated) by a number of endogenous indole derivatives such as kynurenine. In addition to regulating metabolism enzymes, the AhR has roles in regulating immune cells, stem cell maintenance, and cellular differentiation. The aryl hydrocarbon receptor is a member of the family of basic helix-loop-helix transcription factors. AhR binds several exogenous ligands such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B Recognition Element
The B recognition element (BRE) is a DNA sequence found in the promoter region of most genes in eukaryotes and Archaea. The BRE is a cis-regulatory element that is found immediately near TATA box, and consists of 7 nucleotides. There are two sets of BREs: one (BREu) found immediately upstream of the TATA box, with the consensus SSRCGCC; the other (BREd) found around 7 nucleotides downstream, with the consensus RTDKKKK. The BREu was discovered in 1998 by Richard H. EbRichard Ebright and co-workers. The BREd was named in 2005 by Deng and Roberts; such a downstream recognition was reported earlier in 2000 in Tsai and Sigler's crystal structure. Binding The transcription factor II B (TFIIB) recognizes either BRE and binds to it. Both BREs work in conjunction with the TATA box (and TATA box binding protein), and have various effects on levels of transcription. TFIIB uses the cyclin-like repeats to recognize DNA. The C-terminal alpha helix, alpha helices of TFIIB intercalate with the D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
