High-Content Classification Of Nucleocytoplasmic Import Or Export Inhibitors

Transcription factors of the nuclear factor K B family are the paradigm for signaling dependent nuclear translocation and are ideally suited to analysis through image-based chemical genetic screening, The authors describe combining high-content image analysis with a compound screen to identify compounds affecting either nuclear import or export. Validation in silico and in vitro determined an EC50 for the nuclear export blocker leptomycin B of 2.4 ng/mL (4.4 nM). The method demonstrated high selectivity (Z ' > 0.95), speed, and robustness in a screen of a compound collection. It identified the licB protein kinase inhibitor BAY 117082 as an import inhibitor, the p38 mitogen-activated protein (MAP) kinase inhibitor PD98509 as an import enhancer, and phorbol ester as an export inhibitor. The results establish a robust method for identifying compounds regulating nucleocytoplasmic import or export and also implicate MAP kinases in nuclear import of nuclear factor k B.