PIR1, a novel phosphatase that exhibits high affinity to RNA . ribonucleoprotein complexes.

摘要: Protein tyrosine phosphatases are involved in the regulation of important cellular processes such as signal transduction, cell cycle progression, and tumor suppression. Here we report cloning characterization PIR1, a novel member dual-specificity phosphatase subfamily protein phosphatases. PIR1 also contains two stretches arginine-rich sequences. We have shown that recombinant possessed an intrinsic activity on phosphotyrosine-containing substrate. A unique feature this is it binds directly to RNAin vitro with high affinity. In addition, found interacted splicing factors 9G8 SRp30C, possibly through RNA intermediate during yeast two-hybrid screen. exhibited nuclear-staining pattern was sensitive RNase A, but not DNase I, suggesting cells associated and/or ribonucleoprotein particles. Furthermore, fraction showed speckle-staining superimposed factor, SC35. Taken together, our data suggest may participate nuclear mRNA metabolism.