MOLECULAR-CLONING AND EXPRESSION OF A CHLORIDE-ION CHANNEL OF CELL-NUCLEI

Ion channels are known to be present on the plasma membrane of virtual ly all cells and have been found on the membranes of various intracell ular organelles. However, until recently they were believed not to occ ur at the nuclear membrane. In this study we describe the molecular cl oning and characterization of a nuclear ion channel protein, designate d nuclear chloride channel-27 (NCC27), from the human myelomonocytic c ell line, U937. NCC27 is a novel chloride ion channel protein that was found to localize principally to the cell nucleus, Its only known hom ologue is a bovine chloride ion channel protein (p64) believed to loca lize to internal organelles. NCC27 therefore represents the first huma n member of a new class of organellar chloride ion channel proteins.