Abstract: The present invention provides protein single-color and multi-color protein fragment complementation assays for drug discovery, in particular to identify compounds that activate or inhibit cellular pathways. Based on the selection of an interacting protein pair combined with an appropriate PCA reporter such as monomeric enzymes and fluorescent proteins, the assays may be run in high-throughput or high-content mode and may be used in automated screening of libraries of compounds. Methods are described for constructing such assays for one or more steps in a biochemical pathway; testing the effects of compounds from combinatorial, natural product, peptide, antibody, nucleic acid or other diverse libraries on the protein or pathway(s) of interest; and using the results of the screening to identify specific compounds that activate or inhibit the protein or pathway(s) of interest. The development of such assays provides for a broad, flexible and biologically relevant platform for drug discovery.

Abstract: The screening system utilizes dynamic measurements of pathway activity to detect the activities of drugs within cellular pathways. The methods of the invention can be used to identify previously unknown drug activities and therapeutic uses, even for drugs that have been well characterized with standard biochemical assays. We demonstrated the utility of the invention by screening a portion of the known pharmacopeia. We identified dozens of drugs, previously or currently marked for a variety of indications, with surprising and previously-unsuspected activity against ‘hallmark’ cancer pathways. We also showed that over 20 of these drugs indeed have anti-proliferative activity in human tumor cells, underscoring the utility and predictability of the screening system. The methodology will extend the utility of the current pharmacopeia and provide the basis for de novo discovery of drugs with a broad range of therapeutic indications.

Abstract: The present invention discloses a method of treating an individual or animal with diabetes and/or obesity. The method comprises administering to the individual or animal a therapeutically effective amount of a protein tyrosine kinase inhibitor. Preferably, the preventative and therapeutic methods of the present invention involve administering—to a mammal in need thereof—a therapeutically effective amount of an inhibitor of a c-Src-family protein tyrosine kinase. The invention pertains to pharmaceutical compositions containing an inhibitor of a c-Src-family protein tyrosine kinase or an analog or metabolite thereof, or an inhibitor of another protein tyrosine kinase, and a pharmaceutically acceptable carrier. Purines and pyrimidines and other molecules useful in the treatment of diabetes and obesity are provided herein, in particular, pyrazolopyrimidines, cyanoquinolines, phenylaminopyrimidines, anilinoquinazolines and related compounds.

Abstract: The instant invention provides a method for establishing safety profiles for chemical compounds, as well as pharmacological profiling said method comprising (A) testing the effects of said chemical compounds on the amount and/or post-translational modifications of two or more macromolecules in intact cells; (B) constructing a pharmacological profile based on the results of said tests; and (C) comparing said profile to the profile(s) of drugs with established safety characteristics. Additionally, the invention is also directed to a composition comprising an assay panel, said panel comprising at least one high-content assay for the amount and/or post-translational modification of a protein and at least one high-content assay for the amount and/or subcellular location of a protein-protein interaction.

Abstract: The invention features a method for treating a patient having a cancer or other neoplasm, by administering to the patient one of the following drugs or a metabolite or analog thereof: cinnarizine; desipramine; fenofibrate; flunarizine; isoreserpine; nicardipine; promazine; promethazine; suloctidil; terfenadine; atorvastatin; mebeverine; sertraline; albendazole; bepridil; bergaptene; clomiphene; dichlorophene; droperidol; mebendazole; meclocycline; metergoline; ramiphenazone; sanguinarine; dipyrone; nicardipine; or 4-dimethylaminoantipyrine.

Abstract: The present invention describes a method of expressing PCA interacting partners in plant material comprising: (A) transforming said material with: (1) a first construct coding for a first fusion product comprising (a) a first fragment of a first molecule whose fragments can exhibit a detectable activity when associated and (b) a first protein-protein interacting domain; and (2) a second construct coding for a second fusion product comprising (a) a second fragment of said first molecule and (b) a second protein-protein interacting domain that can bind (1)(b); (B) culturing said material under conditions allowing expression of said PCA interacting partners; and (C) detecting said activity.

Abstract: The present invention describes an assay method comprising: (A) generating (1) at least a first fragment of a reporter molecule linked to a first interacting domain and at least a second fragment of a reporter molecule linked to a second interacting domain, or (2) nucleic acid molecules that code for (A)(1) and subsequently allowing said nucleic acid molecules to produce their coded products; then, (B) allowing interaction of said domains; and (C) detecting reconstituted reporter molecule activity, where said reporter molecule can react with a penicillin- or a cephalosporin-class substrate.

Abstract: The present invention provides methods for performing pharmacological profiling of a chemical compound, in particular to improve drug safety and efficacy at an early stage in the drug development process. The chemical compound may be a test compound, drug lead, known drug or toxicant. The compound is profiled against a panel of assays. Preferred embodiments of the invention include high-content assays for protein-protein interactions. The compositions and methods of the invention can be used to identify pathways underlying drug efficacy, safety, and toxicity; and to effect attrition of novel compounds with undesirable or toxic properties. The compositions and methods of the invention can also be used to identify new uses of therapeutic agents, to screen libraries of chemical compounds, to perform lead optimization, and to perform studies of structure-activity relationships in the context of intact cells.

Abstract: The present invention describes a method for detecting biomolecular interactions said method comprising: (a) selecting an appropriate reporter molecule selected from the group consisting of a protein, a fluorescent protein, a luminescent protein and a phosphorescent protein; (b) effecting fragmentation of said reporter molecule such that said fragmentation results in reversible loss of reporter function; (c) fusing or attaching fragments of said reporter molecule separately to other molecules; followed by (d) reassociation of said reporter fragments through interactions of the molecules that are fused to said fragments; and (e) detecting said biomolecular interactions by reconstitution of activity of the reporter molecule with the proviso that said protein is not ubiquitin.

Abstract: The present invention describes a rapid and efficient in vivo library-versus-library screening strategy for identifying optimally interacting pairs of heterodimerizing polypeptides. It allows for the screening of a protein library against a second protein library, rather than against a single bait protein, and thus has numerous applications in the study of protein-protein interactions. Additionally, it allows for the application of different selection stringencies. Two leucine zipper libraries, semi-randomized at the positions adjacent to the hydrophobic core, were genetically fused to either one of two designed fragments of the enzyme murine dihydrofolate reductase (mDHFR), and cotransformed into E. coli. Interaction between the library polypeptides was required for reconstitution of the enzymatic activity of mDHFR, allowing bacterial growth.

Abstract: Protein Fragment Complementation Assays (PCA) are done in plant material using enzyme fragment constructs, for example, dihydrofolate reductase (DHFR) fragment constructs. Plant material is transformed with at least two different constructs that form different products capable of interacting to reconstitute enzymatic activity in the plant material. Detection of the activity can be done using a substrate for the enzyme in the culture medium which, when reacted with the enzyme, is converted to a detectable product. One embodiment uses a substrate that can be enzymatically converted to a detectable fluorescent product. An inducer such as rapamycin or salicylic acid can be added to the culture medium to increase the level of detectable product.

Abstract: The present invention describes an assay method comprising: (A) generating (1) at least a first fragment of a reporter molecule linked to a first interacting domain and at least a second fragment of a reporter molecule linked to a second interacting domain, or (2) nucleic acid molecules that code for (A)(1) and subsequently allowing said nucleic acid molecules to produce their coded products; then, (B) allowing interaction of said domains; and (C) detecting reconstituted reporter molecule activity, where said reporter molecule can react with a penicillin- or a cephalosporin-class substrate.

Abstract: The present invention provides protein fragment complementation assays for drug discovery, in particular to identify compounds that activate or inhibit cellular pathways. Based on the selection of an interacting protein pair combined with an appropriate PCA reporter, the assays may be run in high-throughput or high-content mode and may be used in automated screening of libraries of compounds. The interacting pair may be selected by cDNA library screening; by gene-by-gene interaction mapping; or by prior knowledge of a pathway. Fluorescent and luminescent assays can be constructed using the methods provided herein. The selection of suitable PCA reporters for high-throughput or high-content (high-context) assay formats is described for a diversity of reporters, with particular detail provided for examples of monomeric enzymes and fluorescent proteins.