STRUCTURE, CHROMOSOME LOCALIZATION, AND TISSUE DISTRIBUTION OF THE MOUSE TWIK K+ CHANNEL GENE

We have recently discovered a new class of potassium channels with two pore-forming domains and four membrane-spanning domains. When heterol ogously expressed, these channels produce time-and voltage-independent currents that classify them as background or leak channels. TWIK (for tandem of P domains in a weak inwardly rectifying K+ channel) was the first member of this family to be cloned. Here, we describe the genom ic organization of TWIK in the mouse. The coding sequence as well as t he untranslated sequences are contained in three exons, The twik gene (or KCNK1) has been mapped to chromosome 8, consistent with its locali zation to 1q42-43 in human. The twik gene is expressed in virtually al l mouse tissues. It is most abundantly expressed in brain and moderate ly in other organs such as kidney. The level of expression is increase d in brain and kidney from neonate to adult animals, but the TWIK mess age is also detected during embryogenesis, as early as day 7 post conc eption. (C) 1998 Federation of European Biochemical Societies.