An ATP-regulated, inwardly rectifying potassium channel from rat kidney (ROMK)

With the cloning of ROMK [31] and IRK1 [32], a new family of inwardly rectifying K+ channels has been identified. ROMK channel isoforms are highly and differentially expressed in distal nephron segments of the mammalian kidney. These channels exhibit many of the characteristics of the low conductance, ATP-sensitive K+ channels found in apical membranes of TAL, macula densa, and principal cells that are involved in potassium secretion. Thus ROMK channel isoforms appear to be involved in the formation of these secretory KATP channels. Further characterization of these channels should provide further evidence for their role in the secretory KATP channels and new insights into the function and regulation of these channels.