A Chemical Biology Strategy to Analyze Rheostat-like Protein Kinase-Dependent Regulation

SummaryProtein kinases may function more like variable rheostats rather than two-state switches. However, we lack approaches to properly analyze this aspect of kinase-dependent regulation. To address this, we develop a strategy in which a kinase inhibitor is identified using genetics-based screens, kinase mutations that confer resistance are characterized, and dose-dependent responses of isogenic drug-sensitive and resistant cells to inhibitor treatments are compared. This approach has the advantage that function of wild-type kinase, rather than mutants, is examined. To develop this approach, we focus on Ark1, the fission yeast member of the conserved Aurora kinase family. Applying this approach reveals that proper chromosome compaction in fission yeast needs high Ark1 activity, while other processes depend on significantly lower activity levels. Our strategy is general and can be used to examine the functions of other molecular rheostats.

Graphical AbstractFigure optionsDownload high-quality image (277 K)Download as PowerPoint slideHighlights
► A genetics-based chemical screen leads to a fission yeast Aurora kinase inhibitor
► Inhibitor resistance conferring point mutation in the kinase gene is characterized
► Dose-dependent phenotypes in drug-resistant and sensitive cells are compared
► Key cell division processes depend of different levels of Aurora kinase activity