 KCNQ1 is also essential for the normal function of many different epithelial tissues, but in these non-excitable cells it is thought to be predominantly regulated by KCNE2 or KCNE3.KCNE1 slows the activation of KCNQ1 5-10 fold, increases its unitary conductance 4-fold, eliminates its inactivation, and alters the manner in which KCNQ1 is regulated by other proteins, lipids and small molecules.The association of KCNE1 with KCNQ1 was discovered 8 years after Takumi and colleagues reported the isolation of a fraction of RNA from rat kidney that, when injected into "Xenopus" oocytes, produced an unusually slow-activating, voltage-dependent, potassium-selective current.