Figure 2. Protein complexes formed by subfamily-1 and subfamily-2 ethylene receptors.
(A) Ethylene-receptor protein complexes isolated from plants grown in liquid culture. TAP-tagged versions of the receptors were transgenically expressed in Arabidopsis, solubilized from microsomes by LPC, and analyzed by gel-filtration. TAP-tagged proteins were detected using a rabbit anti-goat IgG antibody coupled to horse-radish peroxidase. (B) Ligand-mediated effects upon the ERS1 and ETR1 ethylene receptor protein complexes. Four-day-old etiolated seedlings from wild-type or ERS1-TAP transgenic plants were treated with the ethylene biosynthesis precursor 50 µM ACC or with 10 µL/L ethylene (C2H4). The ACC treatment was for four days while the ethylene treatment was for 6 hr. Differences of 50 kDa or less are not significant.