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Polypurine Reverse-Hoogsteen Hairpin
Polypurine reverse-Hoogsteen hairpins (PPRHs) are non-modified oligonucleotides containing two polypurine domains, in a mirror repeat fashion, linked by a pentathymidine stretch forming double-stranded DNA stem-loop molecules. The two polypurine domains interact by intramolecular reverse-Hoogsteen bonds allowing the formation of this specific hairpin structure. Properties PPRHs can bind to polypyrimidine stretches in either single- or double stranded DNA by Watson and Crick bonds establishing triple-stranded DNA structures. The formation of PPRHs triplexes takes place at physiological pH. PPRHs provoke a strand displacement. of the homopurine sequence of the target dsDNA, opening the two strands of the DNA. There are two types of PPRHs: i) Template-PPRHs that bind to the template strand of DNA, inhibiting transcription; and ii) Coding-PPRHs that bind to the coding strand of the DNA altering splicing. Both types of PPRHs decrease gene expression. PPRHs present high stability in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligonucleotides
Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small bits of nucleic acids can be manufactured as single-stranded molecules with any user-specified sequence, and so are vital for artificial gene synthesis, polymerase chain reaction (PCR), DNA sequencing, molecular cloning and as molecular probes. In nature, oligonucleotides are usually found as small RNA molecules that function in the regulation of gene expression (e.g. microRNA), or are degradation intermediates derived from the breakdown of larger nucleic acid molecules. Oligonucleotides are characterized by the sequence of nucleotide residues that make up the entire molecule. The length of the oligonucleotide is usually denoted by " -mer" (from Greek ''meros'', "part"). For example, an oligonucleotide of six nucleotides (nt) is a hexamer, while one of 25 nt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telomerase Reverse Transcriptase
Telomerase reverse transcriptase (abbreviated to TERT, or hTERT in humans) is a catalytic subunit of the enzyme telomerase, which, together with the telomerase RNA component (TERC), comprises the most important unit of the telomerase complex. Telomerases are part of a distinct subgroup of RNA-dependent polymerases. Telomerase lengthens telomeres in DNA strands, thereby allowing senescent cells that would otherwise become postmitotic and undergo apoptosis to exceed the Hayflick limit and become potentially immortal, as is often the case with cancerous cells. To be specific, TERT is responsible for catalyzing the addition of nucleotides in a TTAGGG sequence to the ends of a chromosome's telomeres. This addition of repetitive DNA sequences prevents degradation of the chromosomal ends following multiple rounds of replication. hTERT absence (usually as a result of a chromosomal mutation) is associated with the disorder Cri du chat. Function Telomerase is a ribonucleopr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wild Type-PPRH
Wild, wild, wilds or wild may refer to: Common meanings * Wild animal * Wilderness, a wild natural environment * Wildness, the quality of being wild or untamed Art, media and entertainment Film and television * ''Wild'' (2014 film), a 2014 American film from the 2012 book * ''Wild'' (2016 film), a 2016 German film * ''The Wild'', a 2006 Disney 3D animation film * ''Wild'' (TV series), a 2006 American documentary television series * The Wilds (TV series), a 2020 fictional television series Literature * '' Wild: From Lost to Found on the Pacific Crest Trail'' a 2012 non-fiction book by Cheryl Strayed * ''Wild, An elemental Journey'', a 2006 autobiographical book by Jay Griffiths * ''The Wild'' (novel), a 1991 novel by Whitley Strieber * ''The Wild'', a science fiction novel by David Zindell * ''The Wilds'', a 1998 limited-edition horror novel by Richard Laymon Music * ''Wild'' (band), a five-piece classical female group Albums and EPs * ''Wild'' (EP), 2015 * ''Wild'', a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CHEK1
Checkpoint kinase 1, commonly referred to as Chk1, is a serine/threonine-specific protein kinase that, in humans, is encoded by the ''CHEK1'' gene. Chk1 coordinates the DNA damage response (DDR) and cell cycle checkpoint response. Activation of Chk1 results in the initiation of cell cycle checkpoints, cell cycle arrest, DNA repair and cell death to prevent damaged cells from progressing through the cell cycle. Discovery In 1993, Beach and associates initially identified Chk1 as a serine/threonine kinase which regulates the G2/M phase transition in fission yeast. Constitutive expression of Chk1 in fission yeast was shown to induce cell cycle arrest. The same gene called Rad27 was identified in budding yeast by Carr and associates. In 1997, homologs were identified in more complex organisms including the fruit fly, human and mouse. Through these findings, it is apparent Chk1 is highly conserved from yeast to humans. Structure Human Chk1 is located on chromosome 11 on the cytogeni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WEE1
Wee1 is a nuclear kinase belonging to the Ser/Thr family of protein kinases in the fission yeast ''Schizosaccharomyces pombe'' (''S. pombe'')Wee1has a molecular mass of 96 kDa and is a key regulator of cell cycle progression. It influences cell size by inhibiting the entry into mitosis, through inhibiting Cdk1. Wee1 has homologues in many other organisms, including mammals. Introduction The regulation of cell size is critical to ensure functionality of a cell. Besides environmental factors such as nutrients, growth factors and functional load, cell size is also controlled by a cellular cell size checkpoint. Wee1 is a component of this checkpoint. It is a kinase determining the timepoint of entry into mitosis, thus influencing the size of the daughter cells. Loss of Wee1 function will produce smaller than normal daughter cell, because cell division occurs prematurely. Its name is derived from the Scottish dialect word wee, meaning small - its discoverer Paul Nurse w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myc Gene
''Myc'' is a family of regulator genes and proto-oncogenes that code for transcription factors. The ''Myc'' family consists of three related human genes: ''c-myc'' ( MYC), ''l-myc'' ( MYCL), and ''n-myc'' ( MYCN). ''c-myc'' (also sometimes referred to as ''MYC'') was the first gene to be discovered in this family, due to homology with the viral gene ''v-myc''. In cancer, ''c-myc'' is often constitutively (persistently) expressed. This leads to the increased expression of many genes, some of which are involved in cell proliferation, contributing to the formation of cancer. A common human translocation involving ''c-myc'' is critical to the development of most cases of Burkitt lymphoma. Constitutive upregulation of ''Myc'' genes have also been observed in carcinoma of the cervix, colon, breast, lung and stomach. Myc is thus viewed as a promising target for anti-cancer drugs. Unfortunately, Myc possesses several features that render it undruggable such that any anti-cancer d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bcl2
Bcl-2 (B-cell lymphoma 2), encoded in humans by the ''BCL2'' gene, is the founding member of the Bcl-2 family of regulator proteins that regulate cell death ( apoptosis), by either inhibiting (anti-apoptotic) or inducing (pro-apoptotic) apoptosis. It was the first apoptosis regulator identified in any organism. Bcl-2 derives its name from ''B-cell lymphoma 2'', as it is the second member of a range of proteins initially described in chromosomal translocations involving chromosomes 14 and 18 in follicular lymphomas. Orthologs (such as ''Bcl2'' in mice) have been identified in numerous mammals for which complete genome data are available. Like BCL3, BCL5, BCL6, BCL7A, BCL9, and BCL10, it has clinical significance in lymphoma. Isoforms The two isoforms of Bcl-2, Isoform 1, and Isoform 2, exhibit a similar fold. However, results in the ability of these isoforms to bind to the BAD and BAK proteins, as well as in the structural topology and electrostatic potential of the bin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Survivin
Survivin, also called baculoviral inhibitor of apoptosis repeat-containing 5 or BIRC5, is a protein that, in humans, is encoded by the ''BIRC5'' gene. Survivin is a member of the inhibitor of apoptosis (IAP) family. The survivin protein functions to inhibit caspase activation, thereby leading to negative regulation of apoptosis or programmed cell death. This has been shown by disruption of survivin induction pathways leading to increase in apoptosis and decrease in tumour growth. The survivin protein is expressed highly in most human tumours and fetal tissue, but is completely absent in terminally differentiated cells. These data suggest survivin might provide a new target for cancer therapy that would discriminate between transformed and normal cells. Survivin expression is also highly regulated by the cell cycle and is only expressed in the G2-M phase. It is known that Survivin localizes to the mitotic spindle by interaction with tubulin during mitosis and may play a contributing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topoisomerase I
DNA topoisomerases (or topoisomerases) are enzymes that catalyze changes in the topological state of DNA, interconverting relaxed and supercoiled forms, linked (catenated) and unlinked species, and knotted and unknotted DNA. Topological issues in DNA arise due to the intertwined nature of its double-helical structure, which, for example, can lead to overwinding of the DNA duplex during DNA replication and transcription. If left unchanged, this torsion would eventually stop the DNA or RNA polymerases involved in these processes from continuing along the DNA helix. A second topological challenge results from the linking or tangling of DNA during replication. Left unresolved, links between replicated DNA will impede cell division. The DNA topoisomerases prevent and correct these types of topological problems. They do this by binding to DNA and cutting the sugar-phosphate backbone of either one (type I topoisomerases) or both (type II topoisomerases) of the DNA strands. This transien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoogsteen Base Pair
A Hoogsteen base pair is a variation of base-pairing in nucleic acids such as the A•T pair. In this manner, two nucleobases, one on each strand, can be held together by hydrogen bonds in the major groove. A Hoogsteen base pair applies the N7 position of the purine base (as a hydrogen bond acceptor) and C6 amino group (as a donor), which bind the Watson–Crick (N3–C4) face of the pyrimidine base. History Ten years after James Watson and Francis Crick published their model of the DNA double helix, Karst Hoogsteen reported a crystal structure of a complex in which analogues of A and T formed a base pair that had a different geometry from that described by Watson and Crick. Similarly, an alternative base-pairing geometry can occur for G•C pairs. Hoogsteen pointed out that if the alternative hydrogen-bonding patterns were present in DNA, then the double helix would have to assume a quite different shape. Hoogsteen base pairs are observed in alternative structures such as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MTOR
The mammalian target of rapamycin (mTOR), also referred to as the mechanistic target of rapamycin, and sometimes called FK506-binding protein 12-rapamycin-associated protein 1 (FRAP1), is a kinase that in humans is encoded by the ''MTOR'' gene. mTOR is a member of the phosphatidylinositol 3-kinase-related kinase family of protein kinases. mTOR links with other proteins and serves as a core component of two distinct protein complexes, mTOR complex 1 and mTOR complex 2, which regulate different cellular processes. In particular, as a core component of both complexes, mTOR functions as a serine/threonine protein kinase that regulates cell growth, cell proliferation, cell motility, cell survival, protein synthesis, autophagy, and transcription. As a core component of mTORC2, mTOR also functions as a tyrosine protein kinase that promotes the activation of insulin receptors and insulin-like growth factor 1 receptors. mTORC2 has also been implicated in the control and maintenance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
