The average cell contains ~10 million ribosomes, comprised of ~80 ribosomal proteins and 4 rRNAs. Until recently it was thought that all ribosomes were the same. But substantial new evidence has revealed that ribosome heterogeneity provides an additional level of translational control. These different ribosome populations are termed ‘specialised ribosomes. How these specialised ribosomes translate specific mRNA pools remains a mystery. This project aims to understand how changes in ribosome composition alters ribosome structure and how this enables ribosomes to translate specific mRNA pools.
We have discovered differences in ribosome composition in Drosophila melanogaster brain and testis. mRNA translation is particularly important during sperm production and neural function so it will be exciting to understand how this novel mechanism of gene regulation is achieved and how it contributes to brain function and male fertility.
Using a cutting-edge combination of genetics, biochemistry, translatomics and structural biology this project will uncover the structure-function relationship of specialised ribosomes. To understand changes to ribosome structures this project will involve Cryo-EM and to determine which mRNAs specialised ribosomes translate we will use Ribo-Seq. This work has potential to shed light on the underlying mechanism of human diseases caused by mutations to ribosomal proteins e.g. Diamond-Blackfan.
Specialised ribosomes regulate protein synthesis by targeting translation of specific pools of mRNAs through altered ribosome structure.
Objectives and approaches:
1-Determine protein composition of specialised ribosomes; TMT mass spec of in-vivo tagged ribosomal proteins.
2-Structural assessment of specialised ribosomes; Cryo-EM of purified ribosomes.
3-Determine translational output of specialised ribosomes; Ribo-Seq of purified ribosomes.
4-Understand biological importance of specialised ribosomes; CRISPR followed by fertility and behaviour assays of flies.
The concept of specialised ribosomes has only recently emerged. Several
specialised ribosomes have been characterised but what is missing is the
mechanistic link between altered ribosomal structure and function. By combining
cutting-edge approaches, this proposal will tackle this from several diverse and
complementary viewpoints. This project combines structural analysis of
specialised ribosomes (purified and inside cells) with functional assessments
(translational output and fly phenotype) to provide mechanistic insight.
Further further information on Aspden Group: http://aspdenlab.weebly.com
Further information on omics research at Leeds: http://www.leedsomics.org