  GTPases regulate a wide range of cellular processes, such as intracellular
vesicular transport, signal transduction, and protein translation. These
hydrolase enzymes operate as biochemical switches by toggling between an active
guanosine triphosphate (GTP)-bound state and an inactive guanosine diphosphate
(GDP)-bound state. We compare two network motifs, a single-species switch and
an interlinked cascade that consists of two species coupled through positive
and negative feedback loops. We find that interlinked cascades are closer to
the ideal all-or-none switch and are more robust against fluctuating signals.
While the single-species switch can only achieve bistability, interlinked
cascades can be converted into oscillators by tuning the cofactor
concentrations, which catalyse the activity of the cascade. These regimes can
only be achieved with sufficient chemical driving provided by GTP hydrolysis.
In this study, we present a thermodynamically consistent model that can achieve
bistability and oscillations with the same feedback motif.
