Nancy Carrasco et al, in the Feb 1, 96 issue of Nature report
the cloning of the protein that is responsible for the
transport of both sodium (Na+) and iodide (I-) into the rat
thyroid cells, hence the name symporter protein (NIS). The 65
kD protein crosses the cell membrane 12 times and has 25%
sequence homology with the human Na+/glucose cotransporter
protein. Once transported into the thyroid follicular cells,
other thyroid enzymes couple the iodide to the thyroid
hormones. More work is in progress to isolate the cDNA clones
of human NIS. Identification of this protein is the excellent
starting point in characterization of thyroid disorders that
are associated with mutation and aberrant expression of NIS.
IODIDE TRANSPORTER REVEALED
Nancy Carrasco et al, in the Feb 1, 96 issue of Nature report
the cloning of the protein that is responsible for the
transport of both sodium (Na+) and iodide (I-) into the rat
thyroid cells, hence the name symporter protein (NIS). The 65
kD protein crosses the cell membrane 12 times and has 25%
sequence homology with the human Na+/glucose cotransporter
protein. Once transported into the thyroid follicular cells,
other thyroid enzymes couple the iodide to the thyroid
hormones. More work is in progress to isolate the cDNA clones
of human NIS. Identification of this protein is the excellent
starting point in characterization of thyroid disorders that
are associated with mutation and aberrant expression of NIS.
