THYROID-CELL TRANSFORMATION INHIBITS THE EXPRESSION OF A NOVEL RAT PROTEIN-TYROSINE-PHOSPHATASE

We have isolated a rat thyroid cDNA encoding a novel rat receptor-type tyrosine phosphatase protein. This gene, on the basis of its homology to another tyrosine phosphatase, the recently isolated human DEP-1/HP TP eta, has been named r-PTP eta. In rat thyroid cells the r-PTP eta g ene acts as a differentiation marker, Indeed, the block of thyroid cel l differentiation induced by viral and cellular oncogenes is associate d with the inhibition or marked reduction of the expression of this ge ne and its expression is positively regulated by thyrotropin, the phys iological stimulator of thyroid cell growth. (C) 1997 Academic Press.