A 5S rRNA/L5 complex is a precursor to ribosome assembly in mammalian cells

J Cell Biol. 1988 Mar;106(3):545-56. doi: 10.1083/jcb.106.3.545.


A novel 5S RNA-protein (RNP) complex in human and mouse cells has been analyzed using patient autoantibodies. The RNP is small (approximately 7S) and contains most of the nonribosome-associated 5S RNA molecules in HeLa cells. The 5S RNA in the particle is matured at its 3' end, consistent with the results of in vivo pulse-chase experiments which indicate that this RNP represents a later step in 5S biogenesis than a previously described 5S*/La protein complex. The protein moiety of the 5S RNP has been identified as ribosomal protein L5, which is known to be released from ribosomes in a complex with 5S after various treatments of the 60S subunit. Indirect immunofluorescence indicates that the L5/5S complex is concentrated in the nucleolus. L5 may therefore play a role in delivering 5S rRNA to the nucleolus for assembly into ribosomes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Autoantibodies / immunology
  • Cell Nucleolus / analysis*
  • Centrifugation, Density Gradient
  • Electrophoresis, Polyacrylamide Gel
  • Fluorescent Antibody Technique
  • Friend murine leukemia virus
  • HeLa Cells
  • Humans
  • Immunoassay
  • Leukemia, Erythroblastic, Acute
  • RNA Precursors / analysis
  • RNA Precursors / physiology*
  • RNA, Ribosomal / physiology*
  • RNA, Ribosomal, 5S / analysis
  • RNA, Ribosomal, 5S / physiology*
  • Ribonucleoproteins / analysis
  • Ribonucleoproteins / immunology
  • Ribosomal Proteins / analysis
  • Ribosomes / metabolism*
  • Tumor Cells, Cultured


  • Autoantibodies
  • RNA Precursors
  • RNA, Ribosomal
  • RNA, Ribosomal, 5S
  • Ribonucleoproteins
  • Ribosomal Proteins
  • ribosomal protein L5