Processing Of Precursors 4 (POP4)

POP4 encodes one of the protein subunits of the small nucleolar ribonucleoprotein complexes: the endoribonuclease for mitochondrial RNA processing complex and the ribonuclease P complex. The encoded protein is localized to the nucleus and associates directly with the RNA component of these complexes. This protein is involved in processing of precursor RNAs. Alternative splicing results in multiple transcript variants.The deduced 220-amino acid basic protein is rich in arginine and lysine, has nuclear localization sequences, and has a predicted molecular mass of approximately 25 kD. RPP29 is 23% identical to the yeast Pop4 protein. Fluorescent microscopy demonstrated nuclear and nucleolar expression of RPP29. Immunoblot analysis showed that antibodies to RPP14 or RPP29 precipitate native RNase P.