Potassium Intermediate Small Conductance Calcium Activated Channel Subfamily N, Member 4 (KCNN4)

KCNN4 belongs to a family of IK and SK channels.The predicted 427-amino acid sequence of KCNN4 was approximately 40% identical to that of the rat and human SK channel proteins rSK1, rSK2, rSK3 and hSK1. Sequence analysis revealed that, like the SK channel proteins, KCNN4 contained 6 putative transmembrane domains, a conserved pore region, and a leucine zipper-like motif near the C terminus. By Northern analysis, the authors found that KCNN4 was expressed as 2.6-kb and 3.8-kb transcripts in placenta and at lower levels in lung and pancreas. KCNN4 was expressed predominantly as a 2.2-kb mRNA in a variety of tissues, with minor larger transcripts in some tissues.KCNN4 generated a conductance of approximately 12 pS and had a very high affinity for calcium when expressed in Chinese hamster ovary cells.