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RNA Processing, Post-Transcriptional definition: Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.
posttranscriptional RNA processing definition: any alterations made to primary RNA transcripts before leaving the nucleus as mature mRNA; e.g., removing of introns, splicing of exons, addition of cap or a poly-A tail.
genetic terminator element definition: DNA sequences which signal the termination of transcription.
Terminator Regions, Genetic definition: DNA sequences recognized as signals to end GENETIC TRANSCRIPTION.
Transcription, Genetic definition: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
genetic transcription definition: transfer of genetic information from DNA to messenger RNA by DNA-directed RNA polymerase; includes reverse transcription and transcription of early and late genes expressed early in an organism's life cycle or during later development.
transcription definition: The synthesis of either RNA on a template of DNA or DNA on a template of RNA. [ISBN:0198506732 "Oxford Dictionary of Biochemistry and Molecular Biology"]
Transcription definition: A genetic process in which single-stranded RNA with base sequence complementary to a region of plus strand DNA is synthesized by DNA-dependent RNA polymerases. Following the binding of RNA polymerase on the DNA promoter regions, the RNA product is synthesized in a 5' to 3' direction, elongating the DNA strand as the polymerase proceeds down the unwinding and rewinding of the DNA helix.
Transcriptional Activation definition: Processes that stimulate the GENETIC TRANSCRIPTION of a gene or set of genes.
Transcriptional Activation definition: The process by which an unexpressed gene is activated to serve as a transcription template for synthesis of RNA.
Mothers Against Decapentaplegic Homolog 4 definition: The SMAD4 tumor suppressor protein specifically recognizes an eight base pair palindromic DNA sequence and is critical for transmitting TGFB, and related cytokine signals, to the cell nucleus to mediate transcriptional activation of target genes. The MADH4 gene is a cloned gene for Juvenile Polyposis, associated with colon cancer. (from OMIM 600993 and NCI)
transcription termination definition: The process by which transcription is completed; the formation of phosphodiester bonds ceases, the RNA-DNA hybrid dissociates, and RNA polymerase releases the DNA. [ISBN:0716720094]
Transcription Termination definition: Transcription Termination is the cessation of cellular activities involved in the synthesis a nascent RNA transcript.
Transcriptional Coactivator p75 definition: Encoded by human PSIP1 Gene, Transcriptional Coactivator p75 is an alternatively spliced product that shares a 325-aa region with Transcriptional Coactivator p52, but shows distinct coactivator properties. p75 interacts strongly with the VP16 activation domain. p52 is a potent broad-specificity coactivator; p75 is less active for most activation domains. (NCI)
Transcriptional Coactivator p52 definition: Encoded by human PSIP1 Gene, Transcriptional Coactivator p52 is an alternatively spliced product that shares a 325-aa region with Transcriptional Coactivator p75, but shows distinct coactivator properties. p52 interacts strongly with the VP16 activation domain and with components of the general transcriptional machinery. A potent broad-specificity coactivator, p52 interacts with transcriptional activators and general transcription factors, as well as with ASF/SF2 to modulate pre-mRNA splicing. Most p52 appears to be colocalized with ASF/SF2 in the nucleoplasm. p52 may coordinate pre-mRNA splicing and transcriptional activation of class II genes. (NCI)
ETV3 Gene definition: This gene plays a regulatory role in transcription, terminal differentiation and cell cycle arrest.
Transcriptional Repression definition: Decreased expression of some gene product.
SPT5 Protein definition: Believed to be part of a transcriptional-repression protein complex involved in modulating chromatin structure. The SPT5 amino terminus is highly acidic, while the C-terminus contains seven Mitogen-Activated Protein (MAP) Kinase consensus sequences. (OMIM 602102 and NCI)
RNA interference definition: The process by which double-stranded RNAs silence cognate genes. Involves posttranscriptional gene inactivation ('silencing') both of transgenes or dsRNA introduced into a germline, and of the host gene(s) homologous to the transgenes or dsRNA. This silencing is triggered by the introduction of transgenes or double-stranded RNA (dsRNA), and occurs through a specific decrease in the level of mRNA of both host genes and transgenes. [GOC:ems, PMID:11201747, PMID:11713190]
posttranscriptional gene silencing definition: The inactivation of gene expression by a posttranscriptional mechanism. [GOC:mah, PMID:15020054]
RNA Interference definition: A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
RNA interference definition: gene silencing phenomenon or technique whereby specific double stranded RNAs trigger degradation of the homologous mRNA; the specific double stranded RNAs are processed into small interfering RNAs which serve as a guide for cleavage of the homologous mRNA in the RNA induced silencing complex.
RNA Interference definition: Sequence-specific posttranscriptional gene silencing. It is mediated by 21- and 22-nucleotide small interfering RNAs (siRNAs) generated by ribonuclease III cleavage from longer dsRNAs.
Transcriptional Elongation Factors definition: Transcription factors whose primary function is to regulate the rate in which RNA is transcribed.
Silencer Elements, Transcriptional definition: Nucleic acid sequences that are involved in the negative regulation of GENETIC TRANSCRIPTION by chromatin silencing.
transcription repressor activity definition: Any transcription regulator activity that prevents or downregulates transcription. [GOC:mah]
general transcriptional repressor activity definition: Any activity that stops or downregulates transcription of genes globally, and is not specific to a particular gene or gene set. [GOC:mah]
specific transcriptional repressor activity definition: Any activity that stops or downregulates transcription of specific genes or sets of genes. [GOC:mah]
transcription cofactor activity definition: The function that links a sequence-specific transcription factor to the core RNA polymerase II complex but does not bind DNA itself. [PMID:10213677]
regulation of transcription definition: Any process that modulates the frequency, rate or extent of the synthesis of either RNA on a template of DNA or DNA on a template of RNA. [ISBN:0198506732 "Oxford Dictionary of Biochemistry and Molecular Biology"]
Transcriptional Regulation definition: The control of gene expression at the level of RNA transcription.
DNA-Binding Transcriptional Activator NCYM definition: Expressed in fetal brain, lung, liver, and kidney by human NCYM Gene, 109-aa 12-kDa DNA-Binding Transcriptional Activator NCYM contains a helix-loop-helix motif and a basic region. NCYM appears to function as a DNA-binding protein during normal fetal development and is implicated in the pathogenesis of human tumors. The NCYM transcription unit is located on the opposite strand to NMYC, with extensive overlap between the 5-prime ends of the two units. NMYC and NCYM appear to be coregulated under basal growth conditions and in response to retinoic acid. (NCI)
PSIP1 Gene definition: This gene is involved in regulation of transcription. It also plays a role in mediation of pre-mRNA splicing.
Transcription Coactivator definition: A transcription cofactor that activates transcription from a RNA polymerase II promoter but does not bind DNA itself.
Transcription Repressor/Corepressor definition: Transcription Repressor/Corepressor Gene encodes Transcriptional Repressor/Corepressor, proteins that can regulate transcription by binding to the operator and causing repression. (from Glick: Glossary of Biochemistry and Molecular Biology)
MYCNOS Gene definition: This gene plays a role in the transcriptional activation of target genes.
AraC Transcription Factor definition: A transcription factor found in BACTERIA that positively and negatively regulates the expression of proteins required for the uptake and catabolism of L-ARABINOSE.
DBPB Transcriptional Activation Pathway definition: Endothelial cells respond to treatment with the protease thrombin with increased secretion of the PDGF B-chain. This activation occurs at the transcriptional level and a thrombin response element was identified in the promoter of the PDGF B-chain gene. A transcription factor called the DNA-binding protein B (dbpB) mediates the activation of PDGF B-chain transcription in response to thrombin treatment. DbpB is a member of the Y box family of transcription factors and binds to both RNA and DNA. In the absence of thrombin, endothelial cells contain a 50 kD form of dbpB that binds RNA in the cytoplasm and may play a role as a chaperone for mRNA. The 50 kD version of dbpB also binds DNA to regulate genes containing Y box elements in their promoters. Thrombin activation results in the cleavage of dbpB to a 30 kD form. The proteolytic cleavage releases dbpB from RNA in the nucleus, allowing it to enter the nucleus and binds to a regulatory element distinct from the site recognized by the full length 50 kD dbpB. The genes activated by cleaved dbpB include the PDGF B chain. Dephosphorylation of dbpB also regulates nuclear entry and transcriptional activation. RNA digestion in vitro can release dbpB in its active form, suggesting that the protease responsible for dbpB may be closely associated in a complex. Identification of the protease that cleaves dbpB, the mechanisms of phosphorylation and dephosphorylation, and elucidation of the signaling path by which thrombin induces dbpB will provide greater understanding of this novel signaling pathway. (BioCarta)
Post-Transcriptional Regulation definition: Control of genetic expression past the level of messenger transcription.
Post-Transcriptional Regulation definition: Any subcellular or molecular event, process, or condition that regulates the processing of a gene transcription product.
Transcription Elongation definition: The RNA polymerase moves along the DNA template, adding nucleotides to the growing RNA chain in accordance with the sequence of the template or coding strand.
Transcription Regulation Pathway definition: The PML nuclear bodies are ring-shaped nuclear substructures associated with the regulation of transcription, transformation, cell growth, and apoptosis and are characterized by the presence of the protein PML. The activities of PML as a tumor suppressor and apoptosis inducing factor are exerted through the numerous proteins it interacts with in the PML-nuclear bodies including the tumor suppressor p53. DNA damage-induced activation of p53-dependent apoptosis requires PML. PML acts as a coactivator for p53 and increases acetylation of p53 by the transcriptional coactivator CBP. This acetylation of p53 is reversed by the deacetylase SirT1, the human homolog of the yeast gene Sir2, and this deacetylation opposes the transcriptional activation of p53. The tumor suppressor Rb also interacts with the PML nuclear body, increasing transcriptional repression of genes involved in cell cycle progression, suggesting that PML may affect cellular transformation through more than one mechanism. PML interacts directly with Ubc9, which modifies PML through the attachment of the ubiquitin-like peptide Sumo-1. Sumo-1 modification of PML is not necessary for the nuclear bodies to form, but may affect the recruitment of proteins that interact with PML. PML is involved in non-p53 mediated apoptotic pathways, such as DAXX-mediated apoptosis induced by Fas and TNF and regulates the transcriptional repressor activity of Daxx. The sequestration of Daxx by the PML nuclear bodies relieves the repression of other transcription factors like Pax3 by Daxx. Tumor suppression by PML may in general involve the formation of specific regulatory transcription complexes, including those with DAXX, p53 and CBP. Factors that affect the assembly of PML into the PML nuclear bodies affect the proliferation and transformation of cells. Viral early proteins can interact with PML to disrupt the nuclear bodies, allowing increased proliferation of cells and reduced apoptosis, good conditions for DNA virus infection. Another factor that disrupts the formation of PML nuclear bodies is a translocation between the PML and RAR-alpha genes found in acute promyelocytic leukemia (APL) patients. Binding of retinoic acid to the RAR-alpha steroid hormone receptor activates transcription of retinoic-acid responsive genes. The translocation found in APL patients creates two chimeric proteins, RARalpha-PML and PML-RARalpha. Retinoic acid given to APL patients causes the reappearance of nuclear bodies, and the reversal of cellular transformation, affecting a cure for these patients. (BioCarta)
Transcriptional Activation Domain definition: A DNA-binding domain binds to a specific DNA sequence and a transcriptional activation domain interacts with the basal transcriptional machinery. An association of a transcriptional activation domain with a DNA-binding domain promotes the assembly of RNA polymerase II complexes at the TATA box and increase transcription. (NCI)
chromatin silencing by small RNA definition: Repression of transcription by conversion of large regions of DNA into heterochromatin, directed by small RNAs sharing sequence identity to the repressed region. [GOC:dph, GOC:mtg_lung, GOC:ns]
transcription activator activity definition: Any transcription regulator activity required for initiation or upregulation of transcription. [GOC:jl, ISBN:0124325653]
Regulatory Elements, Transcriptional definition: Nucleotide sequences of a gene that are involved in the regulation of GENETIC TRANSCRIPTION.
transcription antitermination definition: Regulation of transcription by a mechanism that allows RNA polymerase to continue transcription beyond a termination site. [ISBN:0198577788, PMID:12456320]
transcriptional attenuation definition: Regulation of transcription through variation in where transcription termination occurs. [GOC:dh, GOC:mlg, ISBN:0198542682]
Gene Regulatory Networks definition: Interacting DNA-encoded regulatory subsystems in the GENOME that coordinate input from activator and repressor TRANSCRIPTION FACTORS during development, cell differentiation, or in response to environmental cues. The networks function to ultimately specify expression of particular sets of GENES for specific conditions, times, or locations.
transcriptional attenuation by ribosome definition: A type of transcriptional regulation at the level of early termination. This process can occur only in prokaryotes, where transcription of an operon into messenger RNA and translation of that mRNA into polypeptides occur simultaneously. The general principle is that alternative mRNA secondary structures occur under different physiological conditions such as available amount of a particular amino acid. One set of conditions favors early termination of transcription. In the classic example of the trp biosynthesis operon, translation of the gene for a short, trp-containing polypeptide called the trp operon leader peptide pauses either at a trp codon (if tryptophan is scarce) or the stop codon (if trp is readily available). In the former situation transcription continues, but in the latter a Rho-independent terminator forms and reduces, or attenuates, expression of the tryptophan biosynthesis genes. Although the polypeptides encoded by leader peptide genes appear not to be stable once their translation is complete, it is suggested by recent studies that their nascent polypeptide chains interact specifically with ribosomes, specific uncharged tRNAs, or other cellular components to inhibit release at the stop codon and improve the function of transcriptional attenuation as a regulatory switch. [GOC:dh, GOC:mlg, ISBN:0198542682]