TransFORM · Translation in cellular context: Elucidating function, organization and regulation with near-atomic models in whole cells

Translation – the fundamental process of protein synthesis catalyzed by ribosomes - has been extensively characterized from a biochemical, structural, and mechanistic perspective. However, how exactly the translation machinery operates as an interconnected system of millions of ribosomes in cells is poorly understood. Within the cell, ribosomes associate with a multitude of regulatory proteins forming a variety of specialized complexes and distributing across cellular space in a manner that depends on cell state. What is the specific composition of those complexes, their significance, and their functional role? How are they defined and regulated by subcellular compartmentalization? How do they change in response to cellular stress? Our TransFORM synergy team brings together experts in method development for in-cell structural biology and the biology of translation to allow us for the first time to attack these fundamental problems. Building on our prior achievements, we aim to synergistically develop novel methods of cryo-electron tomography with imaging across scales in conjunction with crosslinking mass spectrometry and integrative structural modeling for near-atomic structure determination directly in cells. TransFORM will determine the ribosome structural and functional states across the translation cycle in human cells, following distinct 40S, 80S, and disomal particles (80S+80S), in and out of polysomes and across different protein synthesis regimes. We will uncover structural and compositional changes and regulatory mechanisms across cellular space, in adaptation to perturbations by stressors and during viral infection. Our model systems will span from single cells to organoids. TransFORM will provide a detailed and comprehensive in-cell map of the essential process of protein synthesis while delivering innovative methods for the next-generation of in-cell structural biology.