Abstract: The present invention relates to compositions and methods for displaying proteins and polypeptides on the surface of cells and cellular vesicles. Methods and compositions for drug and vaccine delivery using cell surface display systems of the present invention are also disclosed.

Abstract: The present invention relates to a prokaryotic host cell comprising eukaryotic glycosyltransferase activity, where the eukaryotic glycosyltransferase activity is eukaryotic dolichyl-linked UDP-GlcNAc transferase activity and eukaryotic mannosyl-transferase activity. Also disclosed is a method of producing a glycosylated protein by providing a prokaryotic host cell comprising the eukaryotic glycosyltransferase activity and culturing the prokaryotic host cell under conditions effective to produce a glycosylated protein. Another aspect of the present invention pertains to a method for screening bacteria or bacteriophages by expressing one or more glycans on the surface of a bacteria, attaching a label on the one or more glycans on the surface of the bacteria or on the surface of a bacteriophage derived from the bacteria, and analyzing the label in a high-throughput format.

Abstract: The present invention relates to a probiotic cell transformed with a construct suitable to overexpress and display on the surface of the probiotic cell a fusion protein comprising at least a portion of a transport protein coupled to at least a portion of one or more antigenic proteins or peptides. Probiotic-derived vesicles displaying this fusion protein as well as methods of inducing an immune response using the probiotic cells or vesicles are also disclosed.

Abstract: The present invention is directed to a cell-free system for producing a glycosylated protein. This system comprises an isolated oligosaccharyltransferase capable of transferring a glycan from a lipid carrier molecule to a glycoprotein target, one or more isolated glycans, where each glycan is linked to a lipid carrier molecule, and a glycoprotein target comprising one or more glycan acceptor amino acid residues or a nucleic acid molecule encoding said glycoprotein target. The present invention further relates to kits and methods for producing a glycosylated protein in this cell-free system.

Abstract: The present invention relates to an isolated chimeric molecule comprising a degradation domain including a eukaryotic U-box motif and a targeting domain capable of immuno specifically directing the degradation domain to a substrate where the targeting domain is heterologous to the degradation domain. A linker couples the degradation domain to the targeting domain. Also disclosed are compositions as well as methods of treating a disease, substrate silencing, screening agents for therapeutic efficacy against a disease, and methods of screening for disease biomarkers.

Abstract: The present invention provides systems, vectors and methods for isolation of enhanced ligand-binding proteins from combinatorial libraries displayed on the inner membrane of a host cell.

Abstract: The invention provides methods for using the Twin Arginine Translocation pathway in bacteria to produce heterologous polypeptides that have multiple disulfide bonds. Methods of screening polypeptide libraries produced by secretion through the TAT pathway are also provided. The invention provides improved methods for production of heterologous polypeptides having at least one disulfide bond.

Abstract: The present invention relates to a prokaryotic host cell comprising eukaryotic glycosyltransferase activity, where the eukaryotic glycosyltransferase activity is eukaryotic dolichyl-linked UDP-GlcNAc transferase activity and eukaryotic mannosyl-transferase activity. Also disclosed is a method of producing a glycosylated protein by providing a prokaryotic host cell comprising the eukaryotic glycosyltransferase activity and culturing the prokaryotic host cell under conditions effective to produce a glycosylated protein. Another aspect of the present invention pertains to a method for screening bacteria or bacteriophages by expressing one or more glycans on the surface of a bacteria, attaching a label on the one or more glycans on the surface of the bacteria or on the surface of a bacteriophage derived from the bacteria, and analyzing the label in a high-throughput format.

Abstract: The present invention relates to compositions and methods for displaying proteins and polypeptides on the surface of cells and cellular vesicles. Methods and compositions for drug and vaccine delivery using cell surface display systems of the present invention are also disclosed.

Abstract: The present invention relates to compositions and methods for analyzing and modulating (e.g., enhancing or inhibiting) protein-protein interactions. In particular, compositions and methods of the present invention find use in identifying, reconstituting and characterizing protein-protein interactions, identifying binding subunits, and drug screening. The methods and compositions of the invention may also be used to identify agents that may agonize or antagonize a protein-protein interaction (e.g., using test compounds).

Abstract: The present invention provides methods of isolating of leader peptides capable of directing export of heterologous proteins from the bacterial cytoplasm. The methods rely on the screening of libraries of putative leader peptides or of leader peptide mutants for sequences that allow rapid export and thus can rescue a short-lived reporter protein from degradation in the cytoplasm. The mutant leader peptides identified herein are shown to confer significantly higher steady state levels of export not only for short-lived reporter protein but also for other stable, long-lived proteins. These leader peptides can be used to direct or enhance protein secretion. The present invention further discloses methods for the export of cytoplasmically folded protein via the Tat pathway. Proteins having disulfide bonds are first folded within the cytoplasm in suitable oxidizing mutant strains. Such cytoplasmically pre-folded proteins containing disulfide bonds are then exported via the Tat pathway.

Abstract: The present invention relates to the fields of microbiology, molecular biology and protein biochemistry. More particularly, it relates to compositions and methods for analyzing and altering (e.g., enhancing or inhibiting) protein folding and solubility.

Abstract: The invention provides methods for using the Twin Arginine Translocation pathway in bacteria to produce heterologous polypeptides that have multiple disulfide bonds. Methods of screening polypeptide libraries produced by secretion through the TAT pathway are also provided. The invention provides improved methods for production of heterologous polypeptides having at least one disulfide bond.

Abstract: The present invention provides methods of isolating of leader peptides capable of directing export of heterologous proteins from the bacterial cytoplasm. The methods rely on the screening of libraries of putative leader peptides or of leader peptide mutants for sequences that allow rapid export and thus can rescue a short-lived reporter protein from degradation in the cytoplasm. The mutant leader peptides identified herein are shown to confer significantly higher steady state levels of export not only for short-lived reporter protein but also for other stable, long-lived proteins. These leader peptides can be used to direct or enhance protein secretion. The present invention further discloses methods for the export of cytoplasmically folded protein via the Tat pathway. Proteins having disulfide bonds are first folded within the cytoplasm in suitable oxidizing mutant strains. Such cytoplasmically pre-folded proteins containing disulfide bonds are then exported via the Tat pathway.