Intracellular regulatory networks that control cell behaviors are remarkably intricate and involve numerous components. Amidst this apparent complexity is a key organizing feature: scaffolds. Protein scaffolds bind concomitantly to multiple components of a signaling pathway, thereby promoting signal transmission along a common physical “backbone”. Natural systems broadly use scaffold proteins to propagate signals that regulate cell cycle, proliferation, differentiation and motility in species ranging from yeast to human. Furthermore, there is emerging interest in applying synthetic scaffolds to modulate regulatory and metabolic pathways in applications such as generating cellulosic biofuels. Despite its widespread occurrence in natural networks and its potential applications in synthetic circuits, how scaffolds quantitatively control signal transmission is unclear. In this talk, I will describe recent quantitative insights that we have gathered from studies of the Ste5 scaffold in yeast cells. Our results demonstrate that scaffolding allows tunability of signal throughput without disrupting the quality of signal transmission.