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Regulatory Sequence
A regulatory sequence is a segment of a nucleic acid molecule which is capable of increasing or decreasing the expression of specific genes within an organism. Regulation of gene expression is an essential feature of all living organisms and viruses. Description In DNA, regulation of gene expression normally happens at the level of RNA biosynthesis ( transcription). It is accomplished through the sequence-specific binding of proteins ( transcription factors) that activate or inhibit transcription. Transcription factors may act as activators, repressors, or both. Repressors often act by preventing RNA polymerase from forming a productive complex with the transcriptional initiation region ( promoter), while activators facilitate formation of a productive complex. Furthermore, DNA motifs have been shown to be predictive of epigenomic modifications, suggesting that transcription factors play a role in regulating the epigenome. In RNA, regulation may occur at the level of protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleic Acid
Nucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a pentose, 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). If the sugar is ribose, the polymer is RNA; if the sugar is deoxyribose, a variant of ribose, the polymer is DNA. Nucleic acids are chemical compounds that are found in nature. They carry information in cells and make up genetic material. These acids are very common in all living things, where they create, encode, and store information in every living cell of every outline of life forms, life-form on Earth. In turn, they send and express that information inside and outside the cell nucleus. From the inner workings of the cell to the young of a living thing, they contain and provide information via the nucleic acid sequence. This gives the RNA and DNA their unmistakable 'la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Small Molecules
In molecular biology and pharmacology, a small molecule or micromolecule is a low molecular weight (≤ 1000 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm. Many drugs are small molecules; the terms are equivalent in the literature. Larger structures such as nucleic acids and proteins, and many polysaccharides are not small molecules, although their constituent monomers (ribo- or deoxyribonucleotides, amino acids, and monosaccharides, respectively) are often considered small molecules. Small molecules may be used as research tools to probe biological function as well as leads in the development of new therapeutic agents. Some can inhibit a specific function of a protein or disrupt protein–protein interactions. Pharmacology usually restricts the term "small molecule" to molecules that bind specific biological macromolecules and act as an effector, altering the activity or function of the target. Small molecules can have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intrinsically Disordered Proteins
In molecular biology, an intrinsically disordered protein (IDP) is a protein that lacks a fixed or ordered protein tertiary structure, three-dimensional structure, typically in the absence of its macromolecular interaction partners, such as other proteins or RNA. IDPs range from fully unstructured to partially structured and include random coil, molten globule-like Protein aggregation, aggregates, or flexible linkers in large multi-Protein domain, domain proteins. They are sometimes considered as a separate class of proteins along with globular protein, globular, fibrous protein, fibrous and membrane proteins. IDPs are a very large and functionally important class of proteins. They are most numerous in Eukaryote, eukaryotes, with an estimated 30-40% of residues in the eukaryotic proteome located in disordered regions. Disorder is present in around 70% of proteins, either in the form of disordered tails or flexible linkers. Proteins can also be entirely disordered and lack a define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BRD4
Bromodomain-containing protein 4 is a protein that in humans is encoded by the ''BRD4'' gene. BRD4 is a member of the BET (bromodomain and extra terminal domain) family, which also includes BRD2, BRD3, and BRDT. BRD4, similar to other BET family members, contains two bromodomains that recognize acetylated lysine residues. BRD4 also has an extended C-terminal domain with little sequence homology to other BET family members. Structure The two bromodomains in BRD4, termed BD1 and BD2, consist of 4 alpha-helices linked by 2 loops. The ET domain structure is made up of 3 alpha-helices and a loop. The C-terminal domain of BRD4 has been implicated in promoting gene transcription through interaction with the transcription elongation factor P-TEFb and RNA polymerase II. Function The protein encoded by this gene is homologous to the murine protein MCAP, which associates with chromosomes during mitosis, and to the human BRD2 (RING3) protein, a serine/threonine kinase. Eac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Binding Site
DNA binding sites are a type of binding site found in DNA where other molecules may bind. DNA binding sites are distinct from other binding sites in that (1) they are part of a DNA sequence (e.g. a genome) and (2) they are bound by DNA-binding proteins. DNA binding sites are often associated with specialized proteins known as transcription factors, and are thus linked to transcriptional regulation. The sum of DNA binding sites of a specific transcription factor is referred to as its cistrome. DNA binding sites also encompasses the targets of other proteins, like restriction enzymes, site-specific recombinases (see site-specific recombination) and methyltransferases. DNA binding sites can be thus defined as short DNA sequences (typically 4 to 30 base pairs long, but up to 200 bp for recombination sites) that are specifically bound by one or more DNA-binding proteins or protein complexes. It has been reported that some binding sites have potential to undergo fast evolutiona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super-enhancer
Cell differentiation in multicellular organism A multicellular organism is an organism that consists of more than one cell (biology), cell, unlike unicellular organisms. All species of animals, Embryophyte, land plants and most fungi are multicellular, as are many algae, whereas a few organism ...s with different cell types is determined, in each cell type, by the expression of genes under the regulatory control of typical enhancer (genetics), enhancers and super-enhancers. A Enhancer (genetics), typical enhancer(TE), as illustrated in the top panel of the Figure, is a several hundred base pair region of DNA that can bind transcription factors to sequence motifs on the enhancer. The typical enhancer can come in proximity to its target gene through a large chromosome loop. A Mediator (coactivator), Mediator a complex (consisting of about 26 proteins in an interacting structure) communicates #Enhancer_activation_and_implementation, regulatory signals from the enhancer-located DN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription Factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription (genetics), transcription of genetics, genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The function of TFs is to regulate—turn on and off—genes in order to make sure that they are Gene expression, expressed in the desired Cell (biology), cells at the right time and in the right amount throughout the life of the cell and the organism. Groups of TFs function in a coordinated fashion to direct cell division, cell growth, and cell death throughout life; cell migration and organization (body plan) during embryonic development; and intermittently in response to signals from outside the cell, such as a hormone. There are approximately 1600 TFs in the human genome. Transcription factors are members of the proteome as well as regulome. TFs work alone or with other proteins in a complex, by promoting (a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediator (coactivator)
Mediator is a multiprotein complex that functions as a Transcription (genetics), transcriptional coactivator (genetics), coactivator in all eukaryotes. It was discovered in 1990 in the lab of Roger D. Kornberg, recipient of the 2006 Nobel Prize in Chemistry. Mediator complexes interact with transcription factors and RNA polymerase II. The main function of mediator complexes is to transmit signals from the transcription factors to the polymerase. Mediator complexes are variable at the evolutionary, compositional and conformational levels. The first image shows only one "snapshot" of what a particular mediator complex might be composed of, but it certainly does not accurately depict the conformation of the complex ''in vivo''. During evolution, mediator has become more complex. The yeast ''Saccharomyces cerevisiae'' (a simple eukaryote) is thought to have up to 21 subunits in the core mediator (exclusive of the CDK module), while mammals have up to 26. Individual subunits can be ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CTCF
Transcriptional repressor CTCF also known as 11-zinc finger protein or CCCTC-binding factor is a transcription factor that in humans is encoded by the ''CTCF'' gene. CTCF is involved in many cellular processes, including transcriptional regulation, insulator activity, V(D)J recombination and regulation of chromatin architecture. Discovery CCCTC-Binding factor or CTCF was initially discovered as a negative regulator of the chicken c-myc gene. This protein was found to be binding to three regularly spaced repeats of the core sequence CCCTC and thus was named CCCTC binding factor. Function The primary role of CTCF is thought to be in regulating the 3D structure of chromatin. CTCF binds together strands of DNA, thus forming chromatin loops, and anchors DNA to cellular structures like the nuclear lamina. It also defines the boundaries between active and heterochromatic DNA. Since the 3D structure of DNA influences the regulation of genes, CTCF's activity influences the expre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regulation Of Transcription In Mammals
Regulation is the management of complex systems according to a set of rules and trends. In systems theory, these types of rules exist in various fields of biology and society, but the term has slightly different meanings according to context. For example: * in government, typically regulation (or its plural) refers to the delegated legislation which is adopted to enforce primary legislation; including land-use regulation * in economy: regulatory economics * in finance: financial regulation * in business, industry self-regulation occurs through self-regulatory organizations and trade associations which allow industries to set and enforce rules with less government involvement; and, * in biology, gene regulation and metabolic regulation allow living organisms to adapt to their environment and maintain homeostasis; * in psychology, self-regulation theory is the study of how individuals regulate their thoughts and behaviors to reach goals. Forms Regulation in the social, political ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulator (genetics)
An insulator is a type of cis-regulatory element known as a long-range regulatory element. Found in multicellular eukaryotes and working over distances from the promoter element of the target gene, an insulator is typically 300 bp to 2000 bp in length. Insulators contain clustered binding sites for sequence specific DNA-binding proteins and mediate intra- and inter- chromosomal interactions. Insulators function either as an enhancer-blocker or a barrier, or both. The mechanisms by which an insulator performs these two functions include loop formation and nucleosome modifications. There are many examples of insulators, including the CTCF insulator, the ''gypsy'' insulator, and the β-globin locus. The CTCF insulator is especially important in vertebrates, while the ''gypsy'' insulator is implicated in '' Drosophila.'' The β-globin locus was first studied in chicken and then in humans for its insulator activity, both of which utilize CTCF. The genetic implications of ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silencer (genetics)
In genetics, a silencer is a DNA sequence capable of binding transcription regulation factors, called repressors. DNA contains genes and provides the template to produce messenger RNA (mRNA). That mRNA is then translated into proteins. When a repressor protein binds to the silencer region of DNA, RNA polymerase is prevented from transcribing the DNA sequence into RNA. With transcription blocked, the translation of RNA into proteins is impossible. Thus, silencers prevent genes from being expressed as proteins. RNA polymerase, a DNA-dependent enzyme, transcribes the DNA sequences, called nucleotides, in the 3' to 5' direction while the complementary RNA is synthesized in the 5' to 3' direction. RNA is similar to DNA, except that RNA contains uracil, instead of thymine, which forms a base pair with adenine. An important region for the activity of gene repression and expression found in RNA is the 3' untranslated region. This is a region on the 3' terminus of RNA that will not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
