Figure 3.

Some tandem constructs form functional channels when expressed alone in Xenopus oocytes. Tandem constructs were expressed with or without monomer construct of the same β subunit they contain (β2 or β4; 2 ng/μl tandem to 0.5 ng/μl monomer; 46 nl injected/oocyte). The four tandem constructs shown here were the only ones to produce functional receptors when expressed with the corresponding β monomer (n = 5–10). Note that three out of these four tandem constructs produced inward currents to 1 mM ACh also when expressed alone (2 ng/μl injected, n = 4–6). Only the β4_α3 tandem construct failed to produce any inward currents (n = 6) when expressed alone.