Potassium channel that mediates transmembrane potassium transport (By similarity). Might be required for maintenance of rapid intracellular calcium release (By similarity). May act as a potassium counter-ion channel that functions in synchronization with calcium release from intracellular stores (By similarity). Binds phosphatidylinositol 4,5-bisphosphate (PIP2) (PubMed:27698420). Homotrimer; trimerization probably requires binding to phosphatidylinositol 4,5-bisphosphate (PIP2). Belongs to the TMEM38 family.