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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 expressi ... [...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 insulators ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topologically Associating Domain
A topologically associating domain (TAD) is a self-interacting genomic region, meaning that DNA sequences within a TAD physically interact with each other more frequently than with sequences outside the TAD. The median size of a TAD in mouse cells is 880 kb, and they have similar sizes in non-mammalian species. Boundaries at both side of these domains are conserved between different mammalian cell types and even across species and are highly enriched with CCCTC-binding factor (CTCF) and cohesin. In addition, some types of genes (such as transfer RNA genes and housekeeping genes) appear near TAD boundaries more often than would be expected by chance. The functions of TADs are not fully understood and are still a matter of debate. Most of the studies indicate TADs regulate gene expression by limiting the enhancer- promoter interaction to each TAD, however, a recent study uncouples TAD organization and gene expression. Disruption of TAD boundaries are found to be associated with w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulin-like Growth Factor 2
Insulin-like growth factor 2 (IGF-2) is one of three protein hormones that share structural similarity to insulin. The MeSH definition reads: "A well-characterized neutral peptide believed to be secreted by the liver and to circulate in the blood. It has growth-regulating, insulin-like and mitogenic activities. The growth factor has a major, but not absolute, dependence on somatotropin. It is believed to be a major fetal growth factor in contrast to insulin-like growth factor 1 (IGF-1), which is a major growth factor in adults." Gene structure In humans, the gene is located on chromosome 11p15.5, a region which contains numerous imprinted genes. In mice this homologous region is found at distal chromosome 7. In both organisms, ''IGF2'' is imprinted, with expression resulting favourably from the paternally inherited allele. However, in some human brain regions a loss of imprinting occurs resulting in both ''IGF2'' and being transcribed from both parental alleles. The prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cohesin
Cohesin is a protein complex that mediates sister chromatid cohesion, homologous recombination, and DNA looping. Cohesin is formed of SMC3, SMC1, SCC1 and SCC3 ( SA1 or SA2 in humans). Cohesin holds sister chromatids together after DNA replication until anaphase when removal of cohesin leads to separation of sister chromatids. The complex forms a ring-like structure and it is believed that sister chromatids are held together by entrapment inside the cohesin ring. Cohesin is a member of the SMC family of protein complexes which includes Condensin, MukBEF and SMC-ScpAB. Cohesin was separately discovered in budding yeast by Douglas Koshland and Kim Nasmyth. Structure Cohesin is a multi-subunit protein complex, made up of SMC1, SMC3, RAD21 and SCC3 (SA1 or SA2). SMC1 and SMC3 are members of the Structural Maintenance of Chromosomes (SMC) family. SMC proteins have two main structural characteristics: an ATP-binding cassette-like 'head' domain with ATPase activity (form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H19 (gene)
H19 is a gene for a long noncoding RNA, found in humans and elsewhere. H19 has a role in the negative regulation (or limiting) of body weight and cell proliferation. This gene also has a role in the formation of some cancers and in the regulation of gene expression. . The H19 gene is expressed exclusively on one parental allele in a phenomenon known as imprinting. H19 is only transcribed from the maternally inherited allele; the paternal H19 allele is not expressed. H19 was first named ASM (for Adult Skeletal Muscle) because of its expression in adult skeletal muscle ("ASM") in rats. H19 is also known as BWS because aberrant H19 expression can be involved in Beckwith-Wiedemann Syndrome ("BWS"), as well as Silver-Russell syndrome. Epigenetics deregulations at H19 imprinted gene in sperm have been observed associated with male infertility. Gene characterization The H19 gene contains 3 Sp1 binding sites, however these 3 sites are present in a part of the sequence that has shown ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Y Box Binding Protein 1
Y box binding protein 1 also known as Y-box transcription factor or nuclease-sensitive element-binding protein 1 is a protein that in humans is encoded by the ''YBX1'' gene. Clinical significance YBX1 is a potential drug target in cancer therapy. YB-1 helps the replication of adenovirus type 5, a commonly used vector in gene therapy. Thus, YB-1 can cause an "oncolytic" effect in YB-1 positive cancer cells treated with adenoviruses. Interactions Y box binding protein 1 has been shown to interact with: * ANKRD2, * CTCF, * P53, * PCNA, * RBBP6, and * SFRS9 Splicing factor, arginine/serine-rich 9, also known as SFRS9, is a human gene encoding an SR protein involved in splice site selection in alternative splicing. Interactions SFRS9 has been shown to interact with Y box binding protein 1 and NOL3 .... References Further reading * * * * * * * * * * * * * * * * * * * * * External links * {{NLM content Transcription factors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. These products are often proteins, but in non-protein-coding genes such as transfer RNA (tRNA) and small nuclear RNA (snRNA), the product is a functional non-coding RNA. Gene expression is summarized in the central dogma of molecular biology first formulated by Francis Crick in 1958, further developed in his 1970 article, and expanded by the subsequent discoveries of reverse transcription and RNA replication. The process of gene expression is used by all known life—eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and utilized by viruses—to generate the macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenotype, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Lamina
The nuclear lamina is a dense (~30 to 100 nm thick) fibrillar network inside the nucleus of eukaryote cells. It is composed of intermediate filaments and membrane associated proteins. Besides providing mechanical support, the nuclear lamina regulates important cellular events such as DNA replication and cell division. Additionally, it participates in chromatin organization and it anchors the nuclear pore complexes embedded in the nuclear envelope. The nuclear lamina is associated with the inner face of the inner nuclear membrane of the nuclear envelope, whereas the outer face of the outer nuclear membrane is continuous with the endoplasmic reticulum. The nuclear lamina is similar in structure to the nuclear matrix, that extends throughout the nucleoplasm. Structure and composition The nuclear lamina consists of two components, lamins and nuclear lamin-associated membrane proteins. The lamins are type V intermediate filaments which can be categorized as either A-type (lam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleic Acid Notation
The nucleic acid notation currently in use was first formalized by the International Union of Pure and Applied Chemistry (IUPAC) in 1970. This universally accepted notation uses the Roman characters G, C, A, and T, to represent the four nucleotides commonly found in deoxyribonucleic acids (DNA). Given the rapidly expanding role for genetic sequencing, synthesis, and analysis in biology, some researchers have developed alternate notations to further support the analysis and manipulation of genetic data. These notations generally exploit size, shape, and symmetry to accomplish these objectives. IUPAC notation Degenerate base symbols in biochemistry are an IUPAC representation for a position on a DNA sequence that can have multiple possible alternatives. These should not be confused with non-canonical bases because each particular sequence will have in fact one of the regular bases. These are used to encode the consensus sequence of a population of aligned sequences and are used f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription Factors
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of 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 expressed in the desired 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 up to 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 (as an activator), or blocking (as a repressor) the recruitment of RNA po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMARCA5
SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 5 is a protein that in humans is encoded by the ''SMARCA5'' gene. Function The protein encoded by this gene is a member of the ISWI family of proteins. Members of this family have helicase and ATPase activities and are thought to regulate transcription of certain genes by altering the chromatin structure around those genes. The protein encoded by this gene is a component of the chromatin remodeling and spacing factor RSF, a facilitator of the transcription of class II genes by RNA polymerase II. The encoded protein is similar in sequence to the Drosophila ISWI chromatin remodeling protein. Interactions SMARCA5 has been shown to interact with RAD21, Histone deacetylase 2, POLE3, SATB1 SATB1 (special AT-rich sequence-binding protein-1) is a protein which in humans is encoded by the ''SATB1'' gene. Function SATB1, the global chromatin organizer and transcription factor, has emerged ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chd4
Chromodomain-helicase-DNA-binding protein 4 is an enzyme that in humans is encoded by the ''CHD4'' gene. Function The product of this gene belongs to the SNF2/RAD54 helicase family. It represents the main component of the nucleosome remodeling and deacetylase complex and plays an important role in epigenetic transcriptional repression. Patients with dermatomyositis develop antibodies against this protein. Interactions CHD4 has been shown to interact with HDAC1, Histone deacetylase 2, MTA2, SATB1 and Ataxia telangiectasia and Rad3 related. Clinical Mutations in this gene have been associated with a condition known as Sifrim-Hitz-Weiss syndrome.Weiss K, Lazar HP, Kurolap A, Martinez AF, Paperna T, Cohen L, Smeland MF, Wallen S, Solveig H, Keren B, Terhal P, Irving M, Takaku M, Roberts JD, Petrovich RM, Schrier Vergano SA11,12, Kenney A11, Hove H13, DeChene E, Quinonez SC, Colin E, Ziegler A, Rumple M, Jain M, Monteil D, Roeder ER, Nugent K, van Haeringen A, Gambello M, Sant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
