Table 3.

Protein–protein disruption

Aptamer	Ste50–Ste5	Ste11–Ste50	Interaction Target
C1	69.0  ± 5.2	39.8  ± 6.4	Ste11
C4	47.0  ± 13.3	9.9  ± 2.1	Ste50
N3	41.2  ± 4.8	330.8  ± 37.5	Ste5
pGAH-1	100  ± 9.9	100  ± 1.6	—

Disruption of specific protein–protein interactions. Interactions between Ste50–Ste5 and Ste11–Ste50 were measured as β-galactosidase activity from a LexAop–lacZ reporter. Synthesis of the preys was directed from the vector pGAH-1 (O. Hobert, personal communication; see Materials and Methods). For the Ste50–Ste5 interaction, Ste50 was the bait and Ste5 was the prey. For the Ste11–Ste50 interaction, Ste11 was the bait and Ste50 was the prey. Interaction disruption is given as the percentage of β-galactosidase activity in these strains relative to strains in which the aptamers are not expressed. Errors are reported as SD. Note that AptN3, which targets Ste5, disrupts the Ste50–Ste5 interaction but apparently stimulates the Ste50–Ste11 interaction, perhaps by releasing additional Ste11 bait from a complex with Ste5.