Abstract
Protein phosphatase 1 (PP1) regulates several cellular events via interaction with multiple regulatory subunits. The human prostate proteome includes various PP1-interacting proteins; however, a very limited number of interactions is yet characterized and their role in prostate tumorigenesis remains poorly understood. Tctex1 domain-containing protein 4 (TCTEX1D4) was previously identified as a PP1-interacting protein, but its function, as well as the relevance of its interaction with PP1, are virtually unknown. In this study we addressed the role of the PP1/TCTEX1D4 complex in prostate tumorigenesis. We found distinct expression levels and subcellular distributions for TCTEX1D4 and PP1γ in human prostate epithelial normal-like and malignant cells. Moreover, we showed that TCTEX1D4 participates in the regulation of cell proliferation and modulation of microRNAs expression and that its interaction with PP1 controls its function. Taken together, our study provides first evidence for the involvement of the PP1/TCTEX1D4 complex in prostate tumorigenesis.