Signal recognition particle protein 19 is imported into the nucleus by importin 8 (RanBP8) and transportin.

摘要: The signal recognition particle (SRP) is a cytoplasmic RNA-protein complex that targets proteins to the rough endoplasmic reticulum. Although SRP functions in cytoplasm, RNA microinjection and cDNA transfection experiments animal cells, as well genetic analyses yeast, have indicated assembles nucleus. Nonetheless, mechanisms responsible for nuclear-cytoplasmic transport of are largely unknown. Here we show 19 kDa protein subunit mammalian SRP, SRP19, was efficiently imported into nucleus vitro by two members importin β superfamily receptors, 8 transportin; SRP19 also less several other family. transportin known import variety proteins, first function assigned 8. Furthermore, significant pool endogenous located nucleus, nucleolus. Our results at least one specifically family findings add additional evidence nuclear assembly SRP.