Auxiliary BKβ4 subunits promote nanoscale coupling between BK and voltage-gated calcium channels.

BKβ4 promotes nanoscale organization and functional coupling between BK and voltage-gated calcium channels by increasing BK clustering and changing plasma-membrane proximity.

• Why it matters: Precise spatial and temporal Ca2+ control depends on how BK and CaV channels form nanodomains, yet how BKβ4 regulates their nanoscale architecture is unclear.
• What they did: Using proximity ligation assays, electrophysiology, and superresolution STORM microscopy, the study tested how BKβ4 alters BK–CaV nanodomain organization and coupling, with effects compared across CaV subtypes.
• The result: BKβ4–dependent structural changes enhance coupling between Ca2+ influx and BK activation, and both nanodomain organization and coupling depend on the CaV subtype involved.