The snoRNP chaperone snR190 and the Npa1 complex form a macromolecular assembly required for 60S ribosomal subunit maturation
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View abstract on PubMed
Summary
This summary is machine-generated.Researchers discovered a new macromolecular assembly involving the Npa1 complex and snR190 small nucleolar ribonucleoprotein (snoRNP) chaperone. This assembly is crucial for early ribosomal RNA folding and chaperone activity during ribosome synthesis.
Area Of Science
- Molecular Biology
- Cell Biology
- Biochemistry
Background
- Ribosome synthesis is essential for cell function, with early steps of large ribosomal subunit assembly remaining poorly understood in eukaryotes.
- The box C/D small nucleolar ribonucleoprotein (snoRNP) snR190 and the Npa1 complex are implicated in early 25S ribosomal RNA (rRNA) folding in Saccharomyces cerevisiae.
Purpose Of The Study
- To investigate the early events of ribosome biogenesis and the roles of specific protein complexes.
- To characterize the interaction between the Npa1 complex and the snR190 snoRNP.
Main Methods
- Biochemical analysis of macromolecular assemblies.
- Investigating protein-RNA interactions using yeast models.
- Studying the role of specific RNA structures and protein domains.
Main Results
- An independent macromolecular assembly of the Npa1 complex and snR190 snoRNP exists outside pre-ribosomal particles.
- Nop8 protein mediates this assembly and tethers snR190 snoRNP to pre-ribosomal particles via its RNA Recognition Motif (RRM).
- A specific central stem-loop structure in snR190 snoRNA is vital for high-affinity binding to the Npa1 complex, impacting early pre-rRNA processing.
Conclusions
- The Npa1 complex and snR190 snoRNP form a functional unit independent of pre-ribosomal particles.
- Nop8 plays a key role in mediating the assembly and localization of snR190 snoRNP.
- Optimal snoRNP chaperone activity in rRNA folding requires association with auxiliary protein complexes like the Npa1 complex.
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