Fig. 1: Cooperative stabilization interactions are prevalent among proteins that form a stable complex.

A A schematic depiction of the GPS reporter system. The fluorescent signal intensities of RFP, GFP, and the GFP/RFP ratio represent proxies for measuring the protein synthesis, abundance, and stability, respectively, of the protein of interest (POI). B GPS analysis of the proteins labeled above the plots co-expressing the proteins labeled at right. C Cycloheximide (CHX)-chase analysis of HUS1 (top panel) or RAD1 (bottom panel) with/without RAD1 or HUS1 co-expression, respectively. GAPDH serves as a loading control. Blots are representative of three independent experiments. D The synthesis-abundance relationships of HUS1 (top panel) and RAD1 (bottom panel) in response to increasing dosages of RAD1 and HUS1 co-expression (plot 1 to plot 8), respectively, as measured by FACS. Each dot represents data from a single cell. Red dashed lines indicate the expected synthesis-abundance relationship when RAD1 and HUS1 form a heterodimer. E A schematic diagram illustrating the nonlinear synthesis-abundance correlation of a subunit due to an inadequate supply of stabilizing partners. The biphasic profile (black line) represents the differential stability of assembled and free subunits. F GPS analysis of POLR2G and eIF3I with co-expression of indicated RNA polymerase II and eIF3 subunits, respectively. Source data are provided as a source data file.