C35 and MrB inhibition of ligase auto-adenylylation and in vitro “precleaved” deletion in KREL1–TEV and Calmodulin eluates are correlated with MRP1/2 abundance. (A) KREL1 and KREL2 auto-adenylylation activities with various amounts of the KREL1–TEV and calmodulin eluates in the absence or presence of C35 and MrB (at 10 µM). Endogenous KREL1, KREL2, and KREL1-calmodulin fusion (KREL1-CBP) proteins are indicated. (B) In vitro “precleaved” deletion activities of both eluates in increasing amounts of C35 and MrB. (C) Western blot analysis showing the amount of MRP2 proteins in the two protein preparations. The eluates were precipitated with methanol for the purpose of concentrating them, prior to loading on the gel.
