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Sleeping Beauty Transposon System
The ''Sleeping Beauty'' transposon system is a synthetic DNA transposon designed to introduce precisely defined DNA sequences into the chromosomes of vertebrate animals for the purposes of introducing new traits and to discover new genes and their functions. It is a Tc1/mariner-type system, with the transposase resurrected from multiple inactive fish sequences. Mechanism of action The ''Sleeping Beauty'' transposon system is composed of a ''Sleeping Beauty'' (SB) transposase and a transposon that was designed in 1997 to insert specific sequences of DNA into genomes of vertebrate animals. DNA transposons translocate from one DNA site to another in a simple, cut-and-paste manner (Fig. 1). Transposition is a precise process in which a defined DNA segment is excised from one DNA molecule and moved to another site in the same or different DNA molecule or genome. As do all other Tc1/mariner-type transposases, SB transposase inserts a transposon into a TA dinucleotide base pair in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transposon
A transposable element (TE, transposon, or jumping gene) is a nucleic acid sequence in DNA that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. Transposition often results in duplication of the same genetic material. Barbara McClintock's discovery of them earned her a Nobel Prize in 1983. Its importance in personalized medicine is becoming increasingly relevant, as well as gaining more attention in data analytics given the difficulty of analysis in very high dimensional spaces. Transposable elements make up a large fraction of the genome and are responsible for much of the C-value, mass of DNA in a eukaryotic cell. Although TEs are selfish genetic elements, many are important in genome function and evolution. Transposons are also very useful to researchers as a means to alter DNA inside a living organism. There are at least two classes of TEs: Class I TEs or retrotransposons generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Localization Signal
A nuclear localization signal ''or'' sequence (NLS) is an amino acid sequence that 'tags' a protein for import into the cell nucleus by nuclear transport. Typically, this signal consists of one or more short sequences of positively charged lysines or arginines exposed on the protein surface. Different nuclear localized proteins may share the same NLS. An NLS has the opposite function of a nuclear export signal (NES), which targets proteins out of the nucleus. Types Classical These types of NLSs can be further classified as either monopartite or bipartite. The major structural differences between the two are that the two basic amino acid clusters in bipartite NLSs are separated by a relatively short spacer sequence (hence bipartite - 2 parts), while monopartite NLSs are not. The first NLS to be discovered was the sequence PKKKRKV in the SV40 Large T-antigen (a monopartite NLS). The NLS of nucleoplasmin, KR AATKKAGQAKKK, is the prototype of the ubiquitous bipartite signal: two cluster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcriptional Regulation
In molecular biology and genetics, transcriptional regulation is the means by which a cell regulates the conversion of DNA to RNA (transcription), thereby orchestrating gene activity. A single gene can be regulated in a range of ways, from altering the number of copies of RNA that are transcribed, to the temporal control of when the gene is transcribed. This control allows the cell or organism to respond to a variety of intra- and extracellular signals and thus mount a response. Some examples of this include producing the mRNA that encode enzymes to adapt to a change in a food source, producing the gene products involved in cell cycle specific activities, and producing the gene products responsible for cellular differentiation in multicellular eukaryotes, as studied in evolutionary developmental biology. The regulation of transcription is a vital process in all living organisms. It is orchestrated by transcription factors and other proteins working in concert to finely tune t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transgene
A transgene is a gene that has been transferred naturally, or by any of a number of genetic engineering techniques, from one organism to another. The introduction of a transgene, in a process known as transgenesis, has the potential to change the phenotype of an organism. ''Transgene'' describes a segment of DNA containing a gene sequence that has been isolated from one organism and is introduced into a different organism. This non-native segment of DNA may either retain the ability to produce RNA or protein in the transgenic organism or alter the normal function of the transgenic organism's genetic code. In general, the DNA is incorporated into the organism's germ line. For example, in higher vertebrates this can be accomplished by injecting the foreign DNA into the nucleus of a fertilized ovum. This technique is routinely used to introduce human disease genes or other genes of interest into strains of laboratory mice to study the function or pathology involved with that particula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Expression Cassette
An expression cassette is a distinct component of vector DNA consisting of a gene and regulatory sequence to be expressed by a transfected cell. In each successful transformation, the expression cassette directs the cell's machinery to make RNA and protein(s). Some expression cassettes are designed for modular cloning of protein-encoding sequences so that the same cassette can easily be altered to make different proteins. An expression cassette is composed of one or more genes and the sequences controlling their expression. An expression cassette comprises three components: a promoter sequence, an open reading frame, and a 3' untranslated region that, in eukaryotes, usually contains a polyadenylation site. Different expression cassettes can be transfected into different organisms including bacteria, yeast, plants, and mammalian cells as long as the correct regulatory sequences are used. See also * Expression vector * Gene cassette In biology, a gene cassette is a type of mobile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Therapy
Gene therapy is a medical field which focuses on the genetic modification of cells to produce a therapeutic effect or the treatment of disease by repairing or reconstructing defective genetic material. The first attempt at modifying human DNA was performed in 1980, by Martin Cline, but the first successful nuclear gene transfer in humans, approved by the National Institutes of Health, was performed in May 1989. The first therapeutic use of gene transfer as well as the first direct insertion of human DNA into the nuclear genome was performed by French Anderson in a trial starting in September 1990. It is thought to be able to cure many genetic disorders or treat them over time. Between 1989 and December 2018, over 2,900 clinical trials were conducted, with more than half of them in phase I.Gene Therapy Cli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverted Repeats
An inverted repeat (or IR) is a single stranded sequence of nucleotides followed downstream by its reverse complement. The intervening sequence of nucleotides between the initial sequence and the reverse complement can be any length including zero. For example, is an inverted repeat sequence. When the intervening length is zero, the composite sequence is a palindromic sequence. Both inverted repeats and direct repeats constitute types of nucleotide sequences that occur repetitively. These repeated DNA sequences often range from a pair of nucleotides to a whole gene, while the proximity of the repeat sequences varies between widely dispersed and simple tandem arrays. The short tandem repeat sequences may exist as just a few copies in a small region to thousands of copies dispersed all over the genome of most eukaryotes. Repeat sequences with about 10–100 base pairs are known as minisatellites, while shorter repeat sequences having mostly 2–4 base pairs are known as microsa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Recombinases
Recombinases are genetic recombination enzymes. Site specific recombinases DNA recombinases are widely used in multicellular organisms to manipulate the structure of genomes, and to control gene expression. These enzymes, derived from bacteria ( bacteriophages) and fungi, catalyze directionally sensitive DNA exchange reactions between short (30–40 nucleotides) target site sequences that are specific to each recombinase. These reactions enable four basic functional modules: excision/insertion, inversion, translocation and cassette exchange, which have been used individually or combined in a wide range of configurations to control gene expression. Types include: * Cre recombinase * Hin recombinase * Tre recombinase * FLP recombinase Homologous recombination Recombinases have a central role in homologous recombination in a wide range of organisms. Such recombinases have been described in archaea, bacteria, eukaryotes and viruses. Archaea The archaeon ''Sulfolobus solfataricu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrases
Retroviral integrase (IN) is an enzyme produced by a retrovirus (such as HIV) that integrates—forms covalent links between—its genetic information into that of the host cell it infects. Retroviral INs are not to be confused with phage integrases (recombinases) used in biotechnology, such as λ phage integrase, as discussed in site-specific recombination. The macromolecular complex of an IN macromolecule bound to the ends of the viral DNA ends has been referred to as the '' intasome''; IN is a key component in this and the retroviral pre-integration complex. Structure All retroviral IN proteins contain three canonical domains, connected by flexible linkers: ● an N-terminal HH-CC zinc-binding domain (a three-helical bundle stabilized by coordination of a Zn(II) cation) ● a catalytic core domain (RNaseH fold) ● a C-terminal DNA-binding domain ( SH3 fold). Crystal and NMR structures of the individual domains and 2-domain constructs of integrases fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamic Acid
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can synthesize enough for its use. It is also the most abundant excitatory neurotransmitter in the vertebrate nervous system. It serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABA-ergic neurons. Its molecular formula is . Glutamic acid exists in three optically isomeric forms; the dextrorotatory -form is usually obtained by hydrolysis of gluten or from the waste waters of beet-sugar manufacture or by fermentation.Webster's Third New International Dictionary of the English Language Unabridged, Third Edition, 1971. Its molecular structure could be idealized as HOOC−CH()−()2−COOH, with two carboxyl groups −COOH and one amino group −. However, in the solid state and mildly acidic water solutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
