The invention provides an expression and secretion system, and methods of using the same, for the expression and secretion of one fusion protein in prokaryotic cells and a second fusion protein in eukaryotic cells. Also provided herein are nucleic acid molecules, vectors and host cells comprising such vectors and nucleic acid molecules.

Circular nucleic acid vectors that provide for persistently high levels of protein expression are provided. The circular vectors of the subject invention are characterized by being devoid of expression-silencing bacterial sequences, where in many embodiments the subject vectors include a unidirectional site-specific recombination product hybrid sequence in addition to an expression cassette. Also provided are methods of using the subject vectors for introduction of a nucleic acid, e.g., an expression cassette, into a target cell, as well as preparations for use in practicing such methods. The subject methods and compositions find use in a variety of different applications, including both research and therapeutic applications. Also provided is a highly efficient and readily scalable method for producing the vectors employed in the subject methods, as well as reagents and kits/systems for practicing the same.

The present invention provides compositions and methods for programming mammalian cells to perform desired functions. In particular, the present invention provides compositions and methods for programming stem cells to differentiate into a desired cell type. A quorum sensing systems that regulates the expression of cell fate regulators is introduced into mammalian host cells, such as stem cells. The quorum sensing systems generally comprises vectors that express the components of a bacterial quorum sensing pathway, including proteins which catalyze the synthesis of an autoinducer and a gene encoding a regulatory partner of the autoinducer, and vectors in which genes encoding cell fate regulators are operably linked to a promoter induced by the autoinducer/regulatory partner complex. The system can also comprise vectors in which genes encoding additional cell fate regulators are operably linked to a promoter that is induced by a factor synthesized in response to a first stage of differentiation, so that a second stage of differentiation is triggered.

The present invention is related to a nucleic acid molecule, which is also referred to as third nucleic acid molecule, wherein the third nucleic acid molecule comprises (1) a nucleic acid molecule comprising the following elements: (a) optionally, a first part of a genome of a virus; (b) a nucleotide sequence, preferably a genomic nucleotide sequence, or a transcription unit; (c) a regulatory nucleic acid sequence which has a regulatory activity in a prokaryote; (d) exactly one site-specific recombination site; (e) a nucleotide sequence providing for a negative selection marker; (f) a bacterial nucleotide sequence unit comprising (i) bacterial nucleotide sequences for conditional replication and (ii) a nucleotide sequence providing for a positive selection marker; (g) optionally a first restriction site; or (2) a nucleic acid molecule comprising a nucleotide sequence according to SEQ ID NO: 6; or (3) a nucleic acid molecule identical or similar to the nucleic acid molecule contained in the organism deposited with the DSMZ under the Budapest treaty under accession number DSM 23754, wherein preferably the nucleic acid molecule contained in the organism is a heterologous nucleic acid molecule; wherein the third nucleic acid molecule is either a linear or a circular molecule.

The present invention generally relates to improved methods of assembly of two or more DNA fragments, methods of rapid ligation-independent cloning, and kits for rapid ligation-independent cloning and their uses.

UO.sub.2F.sub.2 biosensors, and related U-sensing and/or F-sensing genetic molecular components, genetic circuits, compositions, methods and systems are described, which in several embodiments can be used to detect and/or neutralize uranium and in particular bioavailable UO.sub.2F.sub.2.

The invention provides an expression and secretion system, and methods of using the same, for the expression and secretion of one fusion protein in prokaryotic cells and a second fusion protein in eukaryotic cells. Also provided herein are nucleic acid molecules, vectors and host cells comprising such vectors and nucleic acid molecules.

Methods and compositions are provided for durably influencing microbiological ecosystems (microbiomes) in a subject in order to prevent infection and reduce recurrence of infection by microorganisms. In some embodiments, compositions and methods are provided for the creation and use of molecularly-modified bacterial strains with the potential to prevent a variety of microorganism infections.

The invention relates to mammalian cells comprising at least one prokaryotic two-component signaling (TCS) pathway comprised of an activator protein A, a response regulator (RR) protein B activated by said protein A, such activation leading to an activated RR protein B, and an output gene C operably linked to a promoter. Transcription from said promoter is activated by activated RR protein B, and the expression of output gene C defines at least a first state (0, no transcription) and a second state (1, detectable transcription). The invention further relates to logic gates designed from such cells, and methods for integrating a plurality of output signals based on the cells and logic gates of the invention.

The present invention is directed to a nucleic acid construct comprising a polynucleotide operably linked to one or more control sequence that directs the expression of the polynucleotide in a host cell, wherein at least one control sequence comprises a promoter sequence of an operon comprising a secA gene or a functional fragment or functional variant thereof and wherein said promoter sequence is heterologous to the polynucleotide. In a further embodiment, the invention is directed to an expression vector and a host cell comprising the nucleic acid construct comprising the promoter sequence described herein and a method of expressing a polynucleotide in a host cell.