Novel nuclear protein 1 (NNP-1), also known as RRP1-like protein or Nucleolar protein Nop52, is a 461 amino acid protein belonging to the RRP1 family. Localized to the nucleolus, NNP-1 has simian virus 40-type and bipartite nuclear localization signals and four coiled-coil domains within its C-terminal region. NNP-1 has been found to play an important role in the generation of 28S rRNA in the late processing steps of ribosome biogenesis. At the end of mitosis, nucleolar proteins assemble in a sequential order during the rebuilding of the nucleolus. NNP-1 assembles after Fibrillarin and C23, and simultaneously with B23 and POP1 in the prenucleolar body pathway.