To Explore The Yeast Two RPL36 Paralog Assembled Ribosome Composition And Effect On The Translational Regulation Of Dynamic Change With Physiological Conditions Change

The ribosome is composed of RNA and riboproteins,an RNA-protein complex that is widely found in cells and is mainly involved in protein translation in cells.Traditionally,ribosomes are thought to be a single and monotonous translation machine.In recent years and previous studies in this laboratory have shown that there are many variants of ribosome components in cells,which are not only unique and have physiological background,developmental stages,and specificity of organ tissues.Therefore,it is suspected that changes in ribosome composition are not only Directly affecting the regulation of protein expression may also be involved in many physiological reactions within the cell.Taking a single-copy yeast ribosome as an example,59 of the 78 core proteins have paralogous genes,so theoretically there should be 2⁵⁹ ribosomes based on the“Ribosome Code”hypothesis.It has been reported that there is a difference in the function of ribosomes consisting of two copies of homologous riboproteins,and the reason why the ribosomes composed of two copies of homologous riboproteins differ in function has not been explained so far.The laboratory used yeast riboprotein RPL36 as a target?this protein is a protein encoded by two homologous genes RPL36A and RPL36B?.To enable separation and purification of the two ribosomes,three flags were added to the RPL36A protein.The labeling of three HA tags on RPL36B,combined with sucrose density gradients,co-immunoprecipitation and mass spectrometry analysis,demonstrated that the ribosomes composed of the two riboproteins are indeed different in composition.Different types of LacZ reporter genes were transferred into RPL36double-tagged bacteria and tested for LacZ activity under different physiological conditions.It was found that their translation preference for different types of mRNA did indeed change under different physiological conditions.Based on our further exploration:whether the ribosome composition will change under different physiological conditions?We purified the ribosomes assembled by RPL36A and RPL36B in complete medium and starvation physiological conditions,and sent the purified samples for mass spectrometry detection.Data analysis of the obtained results showed that the composition of RPL36A and RPL36B assembled ribosomes did change under different physiological conditions.We found that the ribosomes assembled by two classes of RPL36 paralogous proteins were reversed under different physiological conditions.We realized that different types of ribosomes not only have different functions,but also have specific physiological conditions.This result demonstrates that in eukaryotic cells,the composition of ribosomes is diverse and changes dynamically with changes in physiological conditions.The results of the pre-laboratory support were due to differences in gene structure that caused the function of two paralogous proteins to be different.When we replaced the promoter of RPL36A with the promoter of ADH1 gene,we did find ribosomes assembled by RPL36A and RPL36B.The composition has changed at the same time,and has led to changes in the translation efficiency of the whole genome under different physiological conditions.These interesting findings allow us to recognize that the means by which cells regulate physiological activity are diverse.The evolution of different types of ribosomes from cells is not a functional redundancy,but rather has a more complex regulatory role and significance,and it can also promote us more.In-depth understanding of the mechanism of translational expression regulation.