The 5S rRNA is associated with Ro60 ribonucleoprotein and is co-precipitated with hYRNAs by anti-Ro antibodies.
Ro particles are conserved molecules that contain a YRNA and various Ro proteins, which are recognized by autoimmune sera from patients with lupus erythematosus or Sjögren's syndrome. The Ro60 ribonucleoprotein (RNP) forms complexes with certain 5S rRNAs, in such a manner that Ro60 could participate in the control of 5S rRNA production. The present studies were carried out to explore the interaction of Ro components, and to address the question whether Ro60 RNP binds simultaneously 5S rRNA and hYRNA. Anti-Ro60 antibodies were used to immunoprecipitate the RNA. Immunoprecipitates were reverse transcribed with specific oligonucleotides and the resulting cDNAs from 5S and hY4 were amplified by PCR. We found that 5S rRNA is complexed with hY4 and hY5 RNAs by means of the Ro60 RNP. Moreover, by in situ hybridization assays we were able to demonstrate that these molecules have a similar nuclear distribution. According to these results, it seems reasonable to assume that the Ro60 protein could be involved in ribosome assembly.
Campos-Almaraz
M
M
Immunotechnology Unit, CBE, Universidad Autónoma de Zacatecas, Guadalupe Zacatecas, México.
Fraire-Velázquez
S
S
Moreno
J
J
Herrera-Esparza
R
R
D000911:Antibodies, Monoclonal / Q000302:isolation & purification; D001324:Autoantigens / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D002467:Cell Nucleus / Q000737:chemistry; D006801:Humans; D008178:Lupus Erythematosus, Cutaneous / Q000097:blood / Q000276:immunology; D046911:Macromolecular Substances; D008970:Molecular Weight; D009707:Nucleosomes / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D012341:RNA, Ribosomal, 5S / Q000276:immunology / Q000378:metabolism*; D020733:RNA, Small Cytoplasmic / Q000276:immunology / Q000378:metabolism*; D012343:RNA, Transfer; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012261:Ribonucleoproteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D000099207:SS-A Antigen
D000911:Antibodies, Monoclonal; D001324:Autoantigens; D046911:Macromolecular Substances; D009707:Nucleosomes; D012341:RNA, Ribosomal, 5S; D020733:RNA, Small Cytoplasmic; D012343:RNA, Transfer; D012261:Ribonucleoproteins; C116006:RO60 protein, human; D000099207:SS-A Antigen