We introduce a formalism to represent and analyze protein–protein and protein–DNA interaction networks. We illustrate the expressivity of this language, by proposing a formal counterpart of Kohn's compilation on the mammalian cell-cycle control. This effectively turns an otherwise static knowledge into a discrete transition system incorporating a qualitative description of the dynamics. We then propose to use the computation tree logic (CTL) as a query language for querying the possible behaviors of the system. We provide examples of biologically relevant queries expressed in CTL about the mammalian cell-cycle control and show the effectiveness of symbolic model checking tools to evaluate CTL queries in this context.