title: Drug-target identification from total cellular lysate by drug-induced conformational changes.
abstract: Identification of drug targets is a key step in the development of novel pharmaceuticals. To this end, chemical probes or affinity matrices are often used, requiring substantial structure-activity relationship (SAR) studies. Here we report on the development of a novel technique for drug-target identification from total cellular lysate conducted independently of SAR information. This technique relies on binding of a drug to its target inducing a conformational change in target protein, thereby altering its susceptibility to proteolysis and resulting in specific degradation in some cases or in protection of target protein in others. As proof of concept, three drugs with identified targets were used. First, incubation of cellular lysates with okadaic acid elicited a specific protective effect on its target, protein phosphatase 2A catalytic subunit. Second, specific protection from exogenous protease of FKBP12 by FK506 and Hsp90 fragments by radicicol were observed. We then used the method to validate the targets of UCS15A, an Src signaling inhibitor. UCS15A induced proteolysis of a number of proteins, one of which was identified as Sam68. These studies suggest that the technology may be generally useful for identification and validation of drug targets.
authors.affiliation: Innovative Drug Research Laboratories, Kyowa Hakko Kirin Co Ltd, Machida-City, Tokyo, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nishiya
authors.forename: Kenji
authors.initials: K
authors.lastname: Shibata
authors.forename: Seiji
authors.initials: S
authors.lastname: Saito
authors.forename: Keiichi
authors.initials: K
authors.lastname: Yano
authors.forename: Chitose
authors.initials: C
authors.lastname: Oneyama
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nakano
authors.forename: Sreenath V
authors.initials: SV
authors.lastname: Sharma
mesh_terms: D001547:Benzaldehydes / Q000494:pharmacology; D002477:Cells; D016503:Drug Delivery Systems; D018942:Macrolides / Q000494:pharmacology; D019319:Okadaic Acid / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000187:drug effects; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D011480:Protease Inhibitors; D011487:Protein Conformation / Q000187:drug effects; D054648:Protein Phosphatase 2 / Q000187:drug effects; D011506:Proteins / Q000737:chemistry / Q000187:drug effects*
chemical_list: D001547:Benzaldehydes; D018942:Macrolides; D004364:Pharmaceutical Preparations; D011480:Protease Inhibitors; D011506:Proteins; C426883:UCS15A; D019319:Okadaic Acid; D054648:Protein Phosphatase 2; D010447:Peptide Hydrolases; C035359:monorden