FIGURE 1.

The S0-S1 linker is palmitoylated in BK channels. A, schematic illustrating the topology of the BK channel pore-forming α-subunit. Sequence alignments of cysteine residues in the S0-S1 linker indicate evolutionary conservation (gray box) across vertebrates, Drosophila and C. elegans. Murine sequence numbered starting from the initiation methionine (MDALI), accession number: AF156674. CSS-Palm prediction scores were determined with the CSS-Palm v2.0 platform. B, representative fluorographs (upper) and Western blots (lower) of full-length ZERO-HA channels and ZERO channels with mutation of key cysteine residues in the S0-S1 linker, expressed in HEK293 cells. Constructs were labeled with [³H]palmitate for 4 h and immunoprecipitated (IP) by using α-HA magnetic microbeads and detected by fluorography. Ratios (normalized to the wild-type ZERO channel) of [³H]palmitate detection in comparison to total protein expression are included.