Issues

Cover picture: Native sumoylation of Kv2.1 in rat hippocampal neurons shown by antibody-mediated FRET (left). Acceptor photobleaching of Alexa Fluor 488 on Kv2.1 (green) and Alexa Fluor 594 on SUMO2/3 reveals interaction at the cell surface (arrowhead), within (open arrow) and at the periphery of Kv2.1 clusters (solid arrow). Sumoylation shifts the conductance–voltage relationship up to 35 mV. Each channel tetramer carries no more than two SUMO1 monomers on lysine 470 of non-adjacent subunits (right); stoichiometry is determined by expression of Kv2.1 and GFP-tagged SUMO1 in CHO cells, TIRF visualization of the cell surface, and stepwise photobleaching (see article by Plant et al., 441–454).