Ribosome biogenesis is tightly regulated to meet the cell's needs. Several mechanisms ensure this regulation:
- Transcriptional Control: The transcription of rRNA genes by RNA polymerase I is regulated by cellular growth signals and nutrient availability. - Post-Transcriptional Modifications: rRNA processing involves modifications like methylation and pseudouridylation, which are regulated by small nucleolar RNAs (snoRNAs) and associated proteins. - Assembly Factors: A myriad of assembly factors assist in the proper folding and assembly of rRNA and ribosomal proteins. - Checkpoint Mechanisms: Quality control checkpoints ensure that only properly assembled ribosomal subunits are transported to the cytoplasm.
