Activation of Potassium transport channels Authored: Mahajan, SS, 2011-05-18 Edited: Mahajan, SS, 2011-05-23 Homotetramers of Kir 1.1 function as inwardly rectifying potassium transport channels. Ki 1.1 are found on the apical side of the cells in the ascending limp of loop of henle and upon activation transport K+ into the extracellular space. Heterotetramers of Kir 4.1 and Ki 5.1 are found on the basolateral side of cells in the distal convoluted tube. Activation of kir 4.1 and 5.1 heterotetramers leads to efflux of K+ into the extracellular space. Pubmed19221509 Reactome Database ID Release 431296045 Reactome, http://www.reactome.org ReactomeREACT_75810 Reviewed: Jassal, B, 2010-09-23