Ribosomes can be compared to a conductor who controls the performance of a symphony, because the process of protein translation is no less complex. The ribosome controls a variety of molecular tools (for example, mRNA and tRNA), which leads to the successful execution of the correct tune (synthesis of proteins with the correct amino acid sequence).
Ribosomes are often thought of as the cell’s molecular factories, deciphering instructions encoded in RNA and “translating” them into protein. The translation ribosome disintegrates either as it reaches the end of the mRNA strand, or due to cellular stress, premature cessation of transcription, mRNA cleavage, or other causes.
Many age-related diseases, including Alzheimer’s and Parkinson’s, are caused by protein aggregation resulting from errors in protein folding. At the same time, the mechanisms that underlie why protein aggregation occurs during aging mostly remain a “black box.”
Age also affects the functioning of ribosomes, the cellular mechanism responsible for the conversion of messenger RNA into proteins.
The increased load of defective proteins with age interferes with the protective quality control that should prevent protein aggregation.
When properly configured, proteins perform their functions, while misfolded proteins, on the contrary, cannot function properly and tend to stick to each other and other proteins, blocking cellular processes and forming toxic aggregates. Protein aggregation is particularly implicated in a wide range of aging-related diseases, including Alzheimer’s, Parkinson’s, and Huntington’s diseases, as well as frontotemporal dementia and amyotrophic lateral sclerosis.
This study shows for the first time that the folding defect during aging starts early in the protein pathway when it is produced by the ribosome. Because ribosomes are constantly producing large amounts of protein, these defects cause a further “snowball” of dysfunction.
The researchers noticed that in old cells, ribosomes periodically moved more slowly and were more likely to stop and collide. As expected, the scientists saw that the decline in proper ribosome performance coincided with an increase in aging-related aggregation of misfolded proteins. One important discovery was that the increase in delays and misfolding exceeded the capacity of the cells’ fail-safe “quality control” systems, which are responsible for proper folding of proteins and elimination of defective ones.
“One of the most vulnerable and pivotal moments in a protein’s life, when it is most prone to misfolding, is the moment of its creation. With age, translation defects lead to system overload, which, in turn, causes an increase in protein aggregates, which themselves are also toxic.”
In conclusion, ribosomes play an extremely important part in protein synthesis. The labelled diagram of ribosome shows its detailed structure. Ribosomes are very important for cell growth, maintenance, and are essential in normal cell functions. Ribosomes are also responsible for producing proteins that are needed for cellular processes.