Identification of thioredoxin targets in Chlamydomonas reinhardtii using an affinity purification approach

Thiol-based redox post-translational modifications have emerged as important mechanisms of signaling and regulation in all organisms. In this context, the small ubiquitous oxido-reductase thioredoxin plays a key role by controlling the thiol-disulfide status of target proteins. Recent redox proteomic studies revealed hundreds of proteins regulated by glutathionylation and nitrosylation in the unicellular green alga Chlamydomonas reinhardtii while much less is known about the thioredoxin interactome in this photosynthetic model organism. Using an affinity purification strategy, we identified 980 thioredoxin targets. They participate in a wide variety of metabolic pathways and cellular processes. This study broadens not only the redox regulation to new enzymes involved in metabolic pathways already known to be regulated by thioredoxins (carbon, lipid and energy metabolism) but also shed light on cellular processes for which data supporting a putative redox regulation in these processes are scarce (aromatic amino-acid biosynthesis, nuclear transport,…).