Protein phosphatase PP6 N terminal domain restricts G1 to S phase progression in human cancer cells.

摘要: Yeast SIT4 is an essential gene encoding a protein Ser/Thr phosphatase conserved throughout eukaryotic evolution, known as PPV in Drosophila and PP6 vertebrates. Sit4 promotes transcription of G1 cyclins sit4(ts) strain exhibits arrest at the restrictive temperature. The yeast was rescued by expression or chimeric containing first fifty-three residues fused to PP1. results suggested that N terminus Sit4/PPV exerts specific function cell cycle. Here we tested whether human effects on G1-S progression cells. PP2A GFP proteins transiently expressed prostate cancer PC-3 Expression fusion restricted lower levels than either GFP. However, blocked entry into S phase increased >20% proportion cells phase. did not significantly change transcripts for ca. eighty other cycle genes, but suppress cyclin D1 reduce phosphorylation RB1 Ser807/811. Thus, our provide evidence regulates least part through control distinct from its homolog yeast.