Extracellular modulation of TREK-2 activity with nanobodies provides insight into the mechanisms of K2P channel regulation by Rödström, KEJ, Cloake, A, Sörmann, J, Baronina, A, Smith, KHM, Pike, ACW, Ang, J, Proks, P, Schewe, M, Holland-Kaye, I, Bushell, SR, Elliott, J, Pardon, E, Baukrowitz, T, Owens, RJ, Newstead, S, Steyaert, J, Carpenter, EP, Tucker, SJ