A 5S rRNA/L5 complex is a precursor to ribosome assembly in mammalian cells.
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.
Steitz
J A
JA
Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06510.
Berg
C
C
Hendrick
J P
JP
La Branche-Chabot
H
H
Metspalu
A
A
Rinke
J
J
Yario
T
T
D000818:Animals; D001323:Autoantibodies / Q000276:immunology; D002466:Cell Nucleolus / Q000032:analysis*; D002499:Centrifugation, Density Gradient; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D005622:Friend murine leukemia virus; D006367:HeLa Cells; D006801:Humans; D007118:Immunoassay; D004915:Leukemia, Erythroblastic, Acute; D012322:RNA Precursors / Q000032:analysis / Q000502:physiology*; D012335:RNA, Ribosomal / Q000502:physiology*; D012341:RNA, Ribosomal, 5S / Q000032:analysis / Q000502:physiology*; D012261:Ribonucleoproteins / Q000032:analysis / Q000276:immunology; D012269:Ribosomal Proteins / Q000032:analysis; D012270:Ribosomes / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D001323:Autoantibodies; D012322:RNA Precursors; D012335:RNA, Ribosomal; D012341:RNA, Ribosomal, 5S; D012261:Ribonucleoproteins; D012269:Ribosomal Proteins; C029742:ribosomal protein L5