Preparations of the 'induced protein' which appears in the rat uterus within 40 min of estradiol administration have recently been reported to contain phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 18.104.22.168) activity. It was found that these two proteins distribute differently on ammonium sulfate fractionation of uterine cytosol. Preparative cellulose acetate electrophoresis afforded complete (>99.9%) separation of phosphoprotein phosphatase activity from the induced protein. The specific activity of phosphoprotein phosphatase in uterine cytosol was unchanged 1, 4, 12, or 24 hr after estradiol administration. These results are incompatible with the view that the induced protein mediates estrogen action by virtue of an inherent phosphoprotein phosphatase activity.
|Number of pages||4|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - 1975|