FIGURE 1:
The K2P channel TASK-1 interacts with the SNARE protein syntaxin-8. (A) The topology of TASK-1 and stx8. (B) Membrane yeast two-hybrid screen with TASK-1 or TASK-3 as bait and stx8 or mutants thereof as prey. The Q179A mutant of stx8 cannot assemble with other SNARE proteins; in the Δ100–140 mutant the linker between the Hc domain and the SNARE domain was excised. (C) RT-PCR analysis of TASK-1 and endosomal SNARE proteins in human brain and in A549 cells. Asterisks represent nonspecific PCR products. (D) Coimmunoprecipitation of stx8 and TASK-1 endogenously expressed in A549 cells. The complex containing TASK-1 was precipitated from cell lysate with a TASK-1–specific antibody from Alomone (APC-024), and a Western blot of the precipitate was probed with TASK-1, stx8, and stx7 antibodies (left); the cell lysate (input) was used as positive control. Coimmunoprecipitation with an unrelated immunoglobulin G antibody (Santa Cruz Biotechnology) was used as a negative control (right).