Figure 1.

In situ interaction of Kv2.1 with syntaxin is dynamic. a, Syntaxin coimmunoprecipitates with Kv2.1 from permeable PC12 cells only after cross-linking of the cells with DTSSP. Permeable PC12 cells, either cross-linked (+DTSSP) or not (−DTSSP), were solubilized under stringent conditions in RIPA buffer (see Materials and Methods), immunoprecipitated by Kv2.1 or synapsin antibodies as indicated above the lanes, and detected by Western blotting with anti-syntaxin antibody. The left and right panels are two separate experiments. The experiments shown are representative of three similar experiments. b, Interaction of Kv2.1 with syntaxin is enhanced after Ca²⁺ triggering of primed cells. Permeable PC12 cells (3 × 10⁶ cells) underwent priming only (primed) or priming followed by triggering (triggered) and were cross-linked with 5 mm DTSSP. Proteins were detected by Western blotting with the corresponding antibodies, as indicated on the right. Lysate (no immunoprecipitation was performed) from 1 × 10⁵ cells was loaded (lysate). IP, Immunoprecipitated; Syx, syntaxin antibody.