Fig. 2. Physical association of [³⁵S]methionine-labelled KCNQ1, KCNE1 and KCNE2 proteins in the in vitro conditions. Complex formations of M2-flag-KCNQ1 with KCNE subunits. Immunoprecipitations with anti-M2-flag antibodies were carried out by using equal volumes of ³⁵S-labelled in vitro translated products corresponding to M2-flag-KCNQ1 (K1), KCNE1 (E1), KCNE2 (E2) and M2-flag-Kv9.3 (Kv9.3), and mixed as follows: lane 1, K1; lane 2, K1 + E1; lane 3, K1 + E2; lane 4, K1 + E1 + E2; lane 5, Kv9.3 + E1; lane 6, Kv9.3 + E2; lane 7, control reaction performed without adding a cRNA in the in vitro translation mixture. White and black arrows indicate the migration of KCNE1 and KCNE2, respectively.