Fig. 2.

Evidence that S440 and S537 are the major AMPK sites on Kv2.1. (A) Kv2.1 in immunoprecipitates made with anti-Kv2.1 (lanes 1–4) or control IgG (lane 5) or in a cell lysate (lane 6) was probed using anti-Kv2.1 or Kv2.1 phosphospecific antibodies. In lane 2, the immunoprecipitates were treated in a first incubation with phosphatase (PP1γ), and in lanes 3 and 4 this incubation was followed by a second incubation with ATP with or without AMPK. (B) Kv2.1 immunoprecipitated from cells expressing WT or S440A/S537A single or double mutants. Precipitates were treated with phosphatase PP1γ and then with [γ-³²P]ATP with or without AMPK.