摘要:
The present invention relates to inducible transcription control sequences for the regulation of gene expression. Specifically, it relates to an transcription control sequence comprising at least two tet operator sequence motifs allowing the binding of tetracycline-dependent transcriptional regulators, wherein each of the said tetracycline-dependent transcriptional regulators binds with respect to its neighbour to an opposite face of the DNA helix, and a minimal promoter comprising a TATA box which is linked at its 5′ end to a general transcription factor binding site. Further, the present invention relates to a vector, a host cell, a plant or a non-human transgenic animal comprising the said transcription control sequence. Also contemplated is a method for regulating the expression of a nucleic acid sequence being operatively linked to the transcription control sequence of the present invention in a host cell, a plant or a non-human transgenic animal.
摘要:
The present invention provides a panel of transcriptional activator fusion proteins which comprises both tetracycline controlled transactivator proteins and reverse tetracycline transactivator proteins. These transactivators have novel phenotypes such as altered basal transcriptional activity in the absence of doxycycline, altered induced transcriptional activity in the presence of doxycycline, or differential induction by tetracycline and analogs of tetracycline.
摘要:
The present invention relates to a method for producing recombinants intended for use in the complete cell-surface protein gp190/MSP1 from plasmodium, especially plasmodium falciparum, as well as the complete DNA sequence of this protein and the appropriate host organisms suited for expressing said sequence, whereby the protein concerned can be entirely synthesized outside the parasite. Also, the inventive method enables sufficient production of above-mentioned protein and its supply as a vaccine. Finally disclosed is a process for stabilizing genes with high At concentration.
摘要:
A method for regulating expression of a tet operator-linked gene in a cell of a subject is disclosed. In one embodiment, the method involves introducing into the cell a nucleic acid molecule encoding a tetracycline-controllable transactivator (tTA), the tTA comprising a Tet repressor operably linked to a polypeptide which directly or indirectly activates transcription in eucaryotic cells; and modulating the concentration of a tetracycline, or analogue thereof, in the subject. Alternatively, in another embodiment, the method involves obtaining the cell from the subject, introducing into the cell a first nucleic acid molecule which operatively links a gene to at least one tet operator sequence, introducing into the cell a second nucleic acid molecule encoding a tTA, to form a modified cell, administering the modified cell to the subject, and modulating the concentration of a tetracycline, or analogue thereof, in the subject. The first and second nucleic acid molecule can be within a single molecule (e.g., in the same vector) or on separate molecules.
摘要:
Transgenic animals carrying two transgenes, the first coding for a transactivator fusion protein comprising a tet repressor and a polypeptide which directly or indirectly activates in eucaryotic cells, and the second comprising a gene operably linked to a minimal promoter operably linked to at least one tet operator sequence, are disclosed. Isolated DNA molecules (e.g., targeting vectors) for integrating a polynucleotide sequence encoding a transactivator of the invention at a predetermined location within a second target DNA molecule by homologous recombination are also disclosed. Transgenic animals having the DNA molecules of the invention integrated at a predetermined location in a chromosome by homologous recombination are also encompassed by the invention. Methods to regulate the expression of a tet operator linked-gene of interest by administering tetracycline or a tetracycline analogue to an animal of the invention are also disclosed. The regulatory system of the invention allows for conditional inactivation or modulation of expression of a gene of interest in a host cell or animal.
摘要:
Transgenic mice carrying a transgene comprising a nucleic acid molecule encoding protein useful for regulating the expression of genes in eukaryotic cells in a highly controlled manner are disclosed. In the regulatory system of the invention, transcription of a tet operator-linked nucleotide sequence is stimulated by a transcriptional activator fusion protein composed of two polypeptides, a first polypeptide which binds to tet operator sequences in the presence of tetracycline operatively linked to a second polypeptide activates transcription in eukaryotic cells. In a preferred embodiment, the transgene encoding the transcriptional activator fusion protein is integrated at a predetermined location within the chromosome of the transgenic mouse.
摘要:
Methods of regulating gene expression in subjects using tetracycline-responsive fusion proteins are disclosed. In one embodiment, the method involves introducing into a cell the subject a nucleic acid molecule encoding a fusion protein which inhibits transcription, the fusion protein comprising a first polypeptide which binds to a tet operator sequence, operatively linked to a heterologous second polypeptide which inhibits transcription in eukaryotic cells; and modulating the concentration of a tetracycline, or analogue thereof, in the subject. The first polypeptide can binds to a tet operator sequence in the absence, but not the presence, of tetracycline. Alternatively, the first polypeptide can binds to a tet operator sequence in the presence, but not the absence, of tetracycline. In another embodiment, the method of the invention involves obtaining a cell from a subject, introducing into the cell a first nucleic acid molecule which operatively links a gene to at least one tet operator sequence, introducing into the cell a second nucleic acid molecule encoding an inhibitory fusion protein of the invention to form a modified cell, administering the modified cell to the subject and modulating the concentration of a tetracycline, or analogue thereof, in the subject. The first and second nucleic acid molecules can be linked or can be separate molecules.
摘要:
Transgenic animals carrying two transgenes, the first coding for a transactivator fusion protein comprising a tet repressor and a polypeptide which directly or indirectly activates in eucaryotic cells, and the second comprising a gene operably linked to a minimal promoter operably linked to at least one tet operator sequence, are disclosed. Isolated DNA molecules (e.g., targeting vectors) for integrating a polynucleotide sequence encoding a transactivator of the invention at a predetermined location within a second target DNA molecule by homologous recombination are also disclosed. Transgenic animals having the DNA molecules of the invention integrated at a predetermined location in a chromosome by homologous recombination are also encompassed by the invention. Methods to regulate the expression of a tet operator linked-gene of interest by administering tetracycline or a tetracycline analogue to an animal of the invention are also disclosed. The regulatory system of the invention allows for conditional inactivation or modulation of expression of a gene of interest in a host cell or animal.
摘要:
Isolated nucleic acid molecules encoding fusion proteins which regulate transcription in eukaryotic cells are disclosed. The fusion proteins of the invention comprise a Tet repressor having at least one amino acid mutation that confers on the fusion protein an ability to bind a class B tet operator sequence having a nucleotide substitution at position +4 or +6, operatively linked to a polypeptide which regulates transcription in eukaryotic cells. Methods for regulating transcription of a tet operator-linked gene in a cell are also provided. In one embodiment, the method involves introducing into the cell a nucleic acid molecule encoding a fusion protein which regulates transcription, the fusion protein comprising a Tet repressor having at least one amino acid mutation that confers on the fusion protein an ability to bind a class B tet operator sequence having a nucleotide substitution at position +4 or +6, operatively linked to a polypeptide which regulates transcription in eukaryotic cells, and modulating the concentration of a tetracycline, or analogue thereof, in contact with the cell.
摘要:
Transcriptional activators which differ in their activation potential by more than 3 orders of magnitude are provided. The transactivators are fusions between a DNA binding protein (e.g., a Tet repressor) and minimal transcriptional activation domains derived from Herpes simplex virus protein 16 (VP16). Substitution mutations at amino acid position 442 within the minimal VP16 domain provide transactivators with differing transactivation ability. Moreover, chimeric activation domains comprising both wild type and mutant minimal VP16 domains provide additional variants with differing transactivation ability. Various aspects of the invention pertain to nucleic acid molecules, vectors, host cells, fusion proteins, transgenic and homologous recombinant organisms and methods of regulating gene transcription.