Review articleDegradation of cytosolic ribosomes by autophagy-related pathways

- Housekeeping turnover of ribosomes is carried out by vacuolar enzymes.
- Ribosomal rRNA transport to the vacuole depends on the presence of ATG5.
- Lack of rRNA recycling causes constitutive autophagy.
- The role of rRNA turnover in cellular homeostasis needs further research.

Ribosomes are essential molecular machines that require a large cellular investment, yet the mechanisms of their turnover are not well understood in any eukaryotic organism. Recent advances in Arabidopsis suggest that plants utilize selective mechanisms to transport rRNA or ribosomes to the vacuole, where rRNA is degraded and the breakdown products recycled to maintain cellular homeostasis. This review focuses on known mechanisms of rRNA turnover and explores unanswered questions on the specificity and pathways of ribosome turnover and the role of this process in maintenance of cellular homeostasis.

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