POLYMERASE CHAIN-REACTIONS USING SACCHAROMYCES, DROSOPHILA AND HUMAN DNA PREDICT A LARGE FAMILY OF PROTEIN SERINE THREONINE PHOSPHATASES

Using the polymerase chain reaction (PCR) to examine the protein serine/threonine phosphatase (PP) family which includes PP1, PP2A and PP2B, we have identified two, seven, and four novel protein phosphatase genes in Saccharomyces cerevisiae, Drosophila melanogaster and Homo sapiens, respectively. Consequently, the genes in the PP1/PP2A/PP2B family now number 11, 15 and 12 in these species respectively, and the data predicts still more unidentified phosphatases in higher eukaryotes. The PCR analyses also point to the presence in Drosophila and mammals of three or more different genes encoding PP2B, the enzyme recently identified as the target of certain immunosuppressant drugs.