Project Details
Projekt
Quantitative, comparative and mechanistic dissection of robustness, adaptability, and limits of the slender chloroplast translation system
Subject Area
Plant Biochemistry and Biophysics
Plant Physiology
Plant Physiology
Term
since 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 437345987
Chloroplasts are endosymbionts of cyanobacterial origin and serve as the plant organelles cen-tral to photosynthesis. They express their genes using a prokaryotic-type translation machinery. During co-evolution with the host cell, the complex regulatory interplay between 70S ribosomes, mRNAs, and tRNAs of the ancestral endosymbiont was streamlined, giving rise to a slender chloroplast translation system that operates with a reduced tRNA set and fewer than 100 reading frames. This minimal setup makes plastid translation ideally suited for dissecting the dynamic range and limitations of the core translation machinery, which is critical for understanding robustness and for modeling protein synthesis. Our interdisciplinary research proposal aims to uncover the fundamental rules and constraints of protein production in chloroplasts by addressing three key questions: How does codon variability affect protein synthesis? How does tRNA availability regulate this process? And how do ribosomes function under stress or when key components of the translation machinery are perturbed? Understanding how codons, tRNAs, and ribosomes dynamically interact under various constraints is crucial. While translation is known to be robust and adaptable, the regulatory inter-connections enabling this flexibility remain largely unresolved.1. We will investigate how the genetic code influences translation efficiency. Our teams will redefine codon usage based on mRNA abundance and translation output and assess how codon preferences shape stress responses. These insights will guide the design of synonymous gene variants to systematically test their impact on translation and support robust predictive modeling. 2. We will quantitatively assess the chloroplast tRNA pool to understand how it supports or limits translation dynamics. By removing or reintroducing specific tRNA genes and identifying compensatory mechanisms, we will reveal how the system maintains robustness and plasticity. These data will feed into detailed computational models simulating how tRNA availability affects translation speed and fidelity. 3. We will analyze translation cycles to explore how ribosomes interact with codons and tRNAs during protein synthesis. Using advanced imaging techniques such as cryo-electron microscopy and tomography, we will capture structural snapshots of ribosomes in distinct elongation states. This will reveal how different codon-tRNA pairings (including standard, wobble, and superwobble interactions) influence translation kinetics and accuracy. By integrating genetics, molecular biology, structural imaging, and computational modeling, our project will deliver a comprehensive, quantitative understanding of protein synthesis in a slender translation system. These findings will advance plant biology, inform synthetic biology and biotechnology, and support the design of minimal cells with tailored protein production and the development of resilient crops.
DFG Programme
Research Grants
