title: An intracellular conformational sensor assay for Abl T315I.
abstract: Conformational change is a common molecular mechanism for the regulation of kinase activities. Small molecule modulators of protein conformations, including allosteric kinase inhibitors, are highly wanted as tools for the interrogation of kinase biology and as selective therapeutic agents. However, straightforward cellular assays monitoring kinase conformations in a manner conducive to high-throughput screening (HTS) are not readily available. Here we describe such an HTS-compatible conformational sensor assay for Abl based on a split luciferase construct. The Abl sensor responds to intramolecular structural rearrangements associated with intracellular Abl deactivation and small molecule inhibition. The intact regulatory CAP-SH3-SH2 domain is required for the full functionality of the sensor. Moreover, a T334I Abl mutant (T315I in Abl1a) was found to be particularly well suited for HTS purposes and mechanistic intracellular studies of T334I mutant inhibitors. We expect that the split luciferase-based conformational sensor approach might be more broadly useful to probe the intracellular activation of other kinases and enzymes in general.
authors.affiliation: Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA.
authors.forename: Vicki
authors.initials: V
authors.lastname: Zhou
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Gao
authors.forename: Shulin
authors.initials: S
authors.lastname: Han
authors.forename: Achim
authors.initials: A
authors.lastname: Brinker
authors.forename: Jeremy S
authors.initials: JS
authors.lastname: Caldwell
authors.forename: Xiang-Ju
authors.initials: XJ
authors.lastname: Gu
mesh_terms: D000818:Animals; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D008156:Luciferases; D020125:Mutation, Missense; D016374:Oncogene Proteins v-abl / Q000032:analysis* / Q000737:chemistry / Q000235:genetics; D011487:Protein Conformation / Q000187:drug effects
chemical_list: D004791:Enzyme Inhibitors; D016374:Oncogene Proteins v-abl; D008156:Luciferases