Genomic structure of the mouse PP4 gene: a developmentally regulated protein phosphatase

Protein phosphatases play important roles in the control of various cellula r processes. Here, we report the cloning and characterization of the murine cDNA and genomic DNA encoding the serine/threonine protein phosphatase 4 ( PP4), also called PPX. While the nucleotide sequences of murine and human P P4 are distinct, their amino acid sequences are identical. We have analyzed the protein, cDNA and genomic PP4 sequences to provide insight into the st ructure, function and potential regulation of PP4. Genomic Southern blots d emonstrated the conservation of PP4 across species. Using Northern blotting and in situ hybridization, we have examined the expression of PP4 in murin e embryos and adult tissues. In adult tissues, PP4 was expressed at high le vels in the testis, kidney, liver, and lung, and at lower levels in virtual ly all tissues. PP4 was differentially expressed in murine embryos at diffe rent developmental stages, suggesting that PP4 is a developmentally regulat ed protein phosphatase. (C) 2001 Elsevier Science B.V. All rights reserved.