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Downstream Promoter Element
In molecular biology, a downstream promoter element (DPE) is a core promoter element. Like all core promoters, the DPE plays an important role in the initiation of gene transcription by RNA polymerase II. The DPE was first described by T. W. Burke and James T. Kadonaga in ''Drosophila melanogaster'' at the University of California, San Diego in 1996. It is also present in other species including humans, but not ''Saccharomyces cerevisiae''. Together with the initiator motif (Inr), another core promoter element, the DPE is recognized by the transcription factor II D (TFIID) subunits TAF6 and TAF9. It has been shown that DPE-dependent basal transcription depends highly on the Inr (and vice versa) and on correct spacing between the two elements. The DPE consensus sequence was originally thought to be RGWCGTG, however more recent studies have suggested it to be the similar but more general sequence RGWYV(T). It is located about 28–33 nucleotides downstream of the Transcription ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Core Promoter Elements
Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (manufacturing), used in casting and molding * Core (optical fiber), the signal-carrying portion of an optical fiber * Core, the central part of a fruit * Hydrophobic core, the interior zone of a protein * Nuclear reactor core, a portion containing the fuel components * Pit (nuclear weapon) or core, the fissile material in a nuclear weapon * Semiconductor intellectual property core (IP core), is a unit of design in ASIC/FPGA electronics and IC manufacturing * Atomic core, an atom with no valence electrons Geology and astrophysics * Core sample, in Earth science, a sample obtained by coring ** Ice core * Core, the central part of a galaxy; see Mass deficit * Core (anticline), the central part of an anticline or syncline * Planetary core, the center of a planet ** Earth's inner core ** Earth's outer core * Stellar core, the region of a star where nuclear fusion takes place * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purine
Purine is a heterocyclic compound, heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted purines and their tautomers. They are the most widely occurring nitrogen-containing heterocycles in nature. Dietary sources Purines are found in high concentration in meat and meat products, especially internal organs such as liver and kidney. In general, plant-based diets are low in purines. High-purine plants and algae include some legumes (lentils and Black-eyed pea, black eye peas) and Spirulina (dietary supplement), spirulina. Examples of high-purine sources include: sweetbreads, Anchovies as food, anchovies, Sardines as food, sardines, liver, beef kidneys, Brain as food, brains, meat extracts (e.g., Oxo (food), Oxo, Bovril), herring, mackerel, scallops, game meats, yeast (beer, yeast extract, nutritional yeast) and g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IRF1
Interferon regulatory factor 1 is a protein that in humans is encoded by the ''IRF1'' gene. Function Interferon regulatory factor 1 was the first member of the interferon regulatory transcription factor (IRF) family identified. Initially described as a transcription factor able to activate expression of the cytokine Interferon beta, IRF-1 was subsequently shown to function as a transcriptional activator or repressor of a variety of target genes. IRF-1 regulates expression of target genes by binding to an interferon stimulated response element (ISRE) in their promoters. The IRF-1 protein binds to the ISRE via an N-terminal helix-turn-helix DNA binding domain, which is highly conserved among all IRF proteins. Beyond its function as a transcription factor, IRF-1 has also been shown to trans-activate the tumour suppressor protein p53 through the recruitment of its co-factor p300. IRF-1 has been shown to play roles in the immune response, regulating apoptosis, DNA damage and tumo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engrailed (gene)
''engrailed'' is a homeodomain transcription factor involved in many aspects of multicellular development. First known for its role in arthropod embryological development, working in consort with the Hox genes, ''engrailed'' has been found to be important in other areas of development. It has been identified in many bilaterians, including the arthropods, vertebrates, echinoderms, molluscs, nematodes, brachiopods, and polychaetes. It acts as a "selector" gene, conferring a specific identity to defined areas of the body, and co-ordinating the expression of downstream genes. Protein ''engrailed (en)'' encodes the homeodomain-containing transcription factor protein Engrailed. Homologous Engrailed proteins are found in a diversity of organisms. When expressed in the ectoderm, ''engrailed'' is involved in the production of skeletal material. ''engrailed'', or genes with very similar sequences, are found in all bilaterian animals. ''engrailed'' plays a number of crucial roles in brai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bride Of Sevenless
''Sevenless'' (''sev'') is a gene in '' Drosophila melanogaster'' that encodes a receptor tyrosine kinase protein essential to the development of R7 cells in the Drosophila embryonic eye. The drosophila ommatidium contains 8 distinct retinula or R cells, each of which has a different spectral sensitivity. The R7 photo receptor, located in each of several ommatidium in the fly's compound eye, is used to detect ultraviolet light. The R8 photo receptor contains an activator of the RTK (receptor tyrosine kinase) for on a precursor R7 cell, called the ''bride of sevenless'' (BOSS). The binding of BOSS to sevenless stimulates a complex series of reactions involving the RTK (sevenless), MAP kinases, Ras and many more molecules to differentiate that precursor R7 photo receptor to a fully functional R7 photo receptor that can see UV light. Much of this knowledge was gained by examining flies with a mutant sevenless which still produced a fully functional R7 photoreceptor when a dominant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antennapedia
''Antennapedia'' (abbreviated ''Antp'') is a Hox gene first discovered in ''Drosophila'' which controls the formation of insect leg, legs during development. Loss-of-function mutations in the regulatory region of this gene result in the development of the second leg pair into Ectopic expression, ectopic Antenna (biology), antennae. By contrast gain-of-function alleles convert antennae into ectopic legs. This is just one illustration of the tendency of organisms to exhibit variations on a theme: modulated repetition. Legs and antennae are related to one another as much as molars are to incisors, fingers are to toes, and arms are to legs. ''Antp'' also refers to a gene complex (ANT-C) in ''Drosophila'' ending with the ''Antp'' gene. It is responsible for formation and differentiation of the Thorax (insect anatomy), thoracic and head segments of the fly's body. Origin of ''Antennapedia''-class homeobox gene The origin of the ancestor homeobox gene is an important aspect of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hox Gene
Hox genes, a subset of homeobox genes, are a group of related genes that specify regions of the body plan of an embryo along the head-tail axis of animals. Hox proteins encode and specify the characteristics of 'position', ensuring that the correct structures form in the correct places of the body. For example, Hox genes in insects specify which appendages form on a segment (for example, legs, antennae, and wings in fruit flies), and Hox genes in vertebrates specify the types and shape of vertebrae that will form. In segmented animals, Hox proteins thus confer segmental or positional identity, but do not form the actual segments themselves. Studies on Hox genes in ciliated larvae have shown they are only expressed in future adult tissues. In larvae with gradual metamorphosis the Hox genes are activated in tissues of the larval body, generally in the trunk region, that will be maintained through metamorphosis. In larvae with complete metamorphosis the Hox genes are mainly express ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Promoter (biology)
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. Promoters control gene expression in bacteria and eukaryotes. RNA polymerase must attach to DNA near a gene for transcription to occur. Promoter DNA sequences provide an enzyme binding site. The -10 sequence is TATAAT. -35 sequences are conserved on average, but not in most promoters. Artificial promoters with conserved -10 and -35 elements transcribe more slowly. All D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TATA Box
In molecular biology, the TATA box (also called the Goldberg–Hogness box) is a sequence of DNA found in the core promoter region of genes in archaea and eukaryotes. The bacterial homolog of the TATA box is called the Pribnow box which has a shorter consensus sequence. The TATA box is considered a non-coding DNA sequence (also known as a cis-regulatory element). It was termed the "TATA box" as it contains a consensus sequence characterized by repeating T and A base pairs. How the term "box" originated is unclear. In the 1980s, while investigating nucleotide sequences in mouse genome loci, the Hogness box sequence was found and "boxed in" at the -31 position. When consensus nucleotides and alternative ones were compared, homologous regions were "boxed" by the researchers. The boxing in of sequences sheds light on the origin of the term "box". The TATA box was first identified in 1978 as a component of eukaryotic promoters. Transcription is initiated at the TATA box in TAT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription (genetics)
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). mRNA comprises only 1–3% of total RNA samples. Less than 2% of the human genome can be transcribed into mRNA ( Human genome#Coding vs. noncoding DNA), while at least 80% of mammalian genomic DNA can be actively transcribed (in one or more types of cells), with the majority of this 80% considered to be ncRNA. Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. Transcription proceeds in the following general steps: # RNA polymerase, together with one or more general transcription factors, binds to promoter DNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth. Nucleotides are obtained in the diet and are also synthesized from common nutrients by the liver. Nucleotides are composed of three subunit molecules: a nucleobase, a five-carbon sugar (ribose or deoxyribose), and a phosphate group consisting of one to three phosphates. The four nucleobases in DNA are guanine, adenine, cytosine and thymine; in RNA, uracil is used in place of thymine. Nucleotides also play a central role in metabolism at a fundamental, cellular level. They provide chemical energy—in the form of the nucleoside triphosphates, adenosine triphosphate (ATP), guanosine triphosphate (GTP), cytidine triphosphate (CTP) and uridine triphosphate (UTP)—throughout the cell for the many cellular func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrimidine
Pyrimidine (; ) is an aromatic, heterocyclic, organic compound similar to pyridine (). One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. The other diazines are pyrazine (nitrogen atoms at the 1 and 4 positions) and pyridazine (nitrogen atoms at the 1 and 2 positions). In nucleic acids, three types of nucleobases are pyrimidine derivatives: cytosine (C), thymine (T), and uracil (U). Occurrence and history The pyrimidine ring system has wide occurrence in nature as substituted and ring fused compounds and derivatives, including the nucleotides cytosine, thymine and uracil, thiamine (vitamin B1) and alloxan. It is also found in many synthetic compounds such as barbiturates and the HIV drug, zidovudine. Although pyrimidine derivatives such as alloxan were known in the early 19th century, a laboratory synthesis of a pyrimidine was not carried out until 1879, when Grimaux reported the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
