Ribosome Recycling - An Essential Process in Protein

Ribosomes are essential organelles involved in protein biosynthesis, found universally in all living organisms. Their primary function is to translate the genetic information stored in messenger RNA (mRNA) into protein chains. This complex process is flawlessly coordinated, happens rapidly, and forms the molecular framework for all forms of life. One key process that contributes to this fine-tuned operation is ribosome recycling, an essential component in the effective production of proteins.

Overview of Ribosome Recycling

Ribosome recycling is the final step in the protein synthesis process, where the ribosome complex disassembles after a protein is made, freeing it to carry out another cycle of protein synthesis. Without this critical step, organisms are left with a build-up of post-termination complexes, leading to a slowing down or cessation of protein synthesis. This process is expertly conducted by ribosome recycling factors (RRF) and elongation factor G (EF-G). In bacteria, this process is relatively well-known. After translation, the 70S ribosome remains bound to the mRNA and the tRNA. This post-translation complex is incapable of initiating another round of protein synthesis without being recycled first. The ribosome recycling phase starts with RRF and EF-G binding to the ribosome and splitting it into the two separate subunits, 50S and 30S, signaling that it is ready for another round of protein assembly. However, despite knowing the process in bacteria, our understanding of ribosome recycling in eukaryotic organisms is significantly less. The presence of a recycling phase is already inferred by the eukaryotic process's cyclical nature. Researchers speculate that the recycling process is complex in higher organisms, unlike in bacteria. This complexity is due to the involvement of other intermediary proteins and the need for energy in the form of GTP molecules. Still, the exact mechanism remains elusive.

Fig. 1 Strategy for ribosome recycling factor (RRF) depletion.¹

Ribosome Recycling and Therapeutic Potential

Understanding ribosome recycling is of profound importance in protein synthesis efficiency. The protein synthesis process consumes a lot of energy in the cell. Prompt and effective recycling of ribosomes leads to fewer resources spent on making new ribosomes. Optimum resource usage is crucial for cellular health and overall survival, especially in rapidly proliferating cells. In addition, ribosome recycling is also a potential target for antimicrobial drugs. For instance, some classes of antibiotics like lincosamides, oxazolidinones, and pleuromutilins interfer with the bacterial protein synthesis by binding to different sites of the 50S subunit of ribosome and inhibiting the RRF binding. Thus, understanding how this process functions extends beyond basic cell biology to medical applications. Unfortunately, the therapeutic potential of targeting ribosome recycling is not fully exploited due to our limited understanding of the process. Given this gap, there is a dire need for research focusing on understanding the mechanics of ribosome recycling in eukaryotes. Investigating the components involved would no doubt open the door to new therapeutic strategies for a variety of diseases.

In summary, ribosome recycling is a critical step in protein synthesis. Despite a superficial understanding of the process in bacteria, there is still much to explore, especially in eukaryotic organisms. Researchers need to decipher this complex yet fundamental mechanism to fully exploit its potential in cellular efficiency and the medical field. This understanding would push the horizons of our knowledge in cell biology and create a pathway toward new therapeutic options for various diseases.

Creative Biolabs has a team of experienced professionals specializing in the field of ribosomal research, offering a wide range of services including but not limited to custom Ribosome Separation and Extraction Services and Ribosome Analysis Services for global clients. If you have any related needs, please feel free to contact us for more information and a detailed quote.

Reference

1. Saito, Kazuki, Rachel Green, and Allen R. Buskirk. "Ribosome recycling is not critical for translational coupling in Escherichia coli." Elife 9 (2020): e59974.