Hierarchical Recruitment into Nascent Ribosomes of Assembly Factors Required for 27SB Pre-rRNA Processing in Saccharomyces Cerevisiae
Overview
Affiliations
To better define the roles of assembly factors required for eukaryotic ribosome biogenesis, we have focused on one specific step in maturation of yeast 60 S ribosomal subunits: processing of 27SB pre-ribosomal RNA. At least 14 assembly factors, the 'B-factor' proteins, are required for this step. These include most of the major functional classes of assembly factors: RNA-binding proteins, scaffolding protein, DEAD-box ATPases and GTPases. We have investigated the mechanisms by which these factors associate with assembling ribosomes. Our data establish a recruitment model in which assembly of the B-factors into nascent ribosomes ultimately leads to the recruitment of the GTPase Nog2. A more detailed analysis suggests that this occurs in a hierarchical manner via two largely independent recruiting pathways that converge on Nog2. Understanding recruitment has allowed us to better determine the order of association of all assembly factors functioning in one step of ribosome assembly. Furthermore, we have identified a novel subcomplex composed of the B-factors Nop2 and Nip7. Finally, we identified a means by which this step in ribosome biogenesis is regulated in concert with cell growth via the TOR protein kinase pathway. Inhibition of TOR kinase decreases association of Rpf2, Spb4, Nog1 and Nog2 with pre-ribosomes.
The novel ribosome biogenesis inhibitor usnic acid blocks nucleolar pre-60S maturation.
Kofler L, Grundmann L, Gerhalter M, Prattes M, Merl-Pham J, Zisser G Nat Commun. 2024; 15(1):7511.
PMID: 39209816 PMC: 11362459. DOI: 10.1038/s41467-024-51754-3.
Mitterer V, Hamze H, Kunowska N, Stelzl U, Henras A, Hurt E Nucleic Acids Res. 2023; 52(4):1975-1987.
PMID: 38113283 PMC: 10899779. DOI: 10.1093/nar/gkad1206.
Mechanism of 5S RNP recruitment and helicase-surveilled rRNA maturation during pre-60S biogenesis.
Lau B, Huang Z, Kellner N, Niu S, Berninghausen O, Beckmann R EMBO Rep. 2023; 24(7):e56910.
PMID: 37129998 PMC: 10328080. DOI: 10.15252/embr.202356910.
Concurrent remodelling of nucleolar 60S subunit precursors by the Rea1 ATPase and Spb4 RNA helicase.
Mitterer V, Thoms M, Buschauer R, Berninghausen O, Hurt E, Beckmann R Elife. 2023; 12.
PMID: 36929751 PMC: 10154028. DOI: 10.7554/eLife.84877.
Archaea/eukaryote-specific ribosomal proteins - guardians of a complex structure.
Kisly I, Tamm T Comput Struct Biotechnol J. 2023; 21:1249-1261.
PMID: 36817958 PMC: 9932298. DOI: 10.1016/j.csbj.2023.01.037.