The composition and turnover of the Arabidopsis thaliana 80S cytosolic ribosome

Karzan Jalal Salih, Owen Duncan, Lei Li, Josua Trösch, A Harvey Millar

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Cytosolic 80S ribosomes contain proteins of the mature cytosolic ribosome (r-proteins) as well as proteins with roles in ribosome biogenesis, protein folding or modification. Here we refined the core r-protein composition in Arabidopsis thaliana by determining the abundance of different proteins during enrichment of ribosomes from cell cultures using peptide mass spectrometry. The turnover rates of 26 40S subunit r-proteins and 29 60S subunit r-proteins were also determined, showing that half of the ribosome population is replaced every 3-4 days. Three enriched proteins showed significantly shorter half-lives; a protein annotated as a ribosomal protein uL10 (RPP0D, At1g25260) with a half-life of 0.5 days and RACK1b and c with half-lives of 1-1.4 days. The At1g25260 protein is a homolog of the human Mrt4 protein, a trans-acting factor in the assembly of the pre-60S particle, while RACK1 has known regulatory roles in cell function beyond its role in the 40S subunit. Our experiments also identified 58 proteins that are not from r-protein families but co-purify with ribosomes and co-express with r-proteins; 26 were enriched more than 10-fold during ribosome enrichment. Some of these enriched proteins have known roles in translation, while others are newly proposed ribosome-associated factors in plants. This analysis provides an improved understanding of Arabidopsis thaliana ribosome protein content, shows that most r-proteins turnover in unison in vivo, identifies a novel set of potential plant translatome components, and how protein turnover can help identify r-proteins involved in ribosome biogenesis or regulation in plants.

Original languageEnglish
Pages (from-to)3019-3032
JournalThe Biochemical journal
Volume477
Issue number16
DOIs
Publication statusPublished - 26 Aug 2020

Fingerprint Dive into the research topics of 'The composition and turnover of the <i>Arabidopsis thaliana</i> 80S cytosolic ribosome'. Together they form a unique fingerprint.

Cite this