Synaptotamin I interacts with Kv1.4 coexpressed in HEK 293 T cells. (A) Recombinant full-length synaptotagmin I was expressed alone or coexpressed with Kv1.4 in HEK293T cells, and immunoprecipitations were performed using extract from the transfected cells. Probe of precipitated proteins with western blot indicated that Kv1.4 was coprecipitated with a polyclonal antibody against synaptotagmin I. Syt I, synaptotagmin I. (B) Subcellular localization of synaptotagmin I and Kv1.4 in HEK293T cells. Cells were incubated with Hochest 33342 (a) and transiently transfected with Kv1.4 cDNA (b), synaptotagmin I cDNA (c), and the combinations of Kv1.4 and synaptotagmin I cDNAs (d), respectively.