Rubisco functional integrity requires a dedicated three-step maturation pathway
Year: 2026
Type: article
Abstract: Proteins generally begin with methionine, which is often removed to expose the second residue. RuBP carboxylase/oxygenase (Rubisco), the most abundant enzyme on Earth and a major carbon and nitrogen reservoir, escapes this paradigm. Its catalytic subunit, RbcL, undergoes unusual amino terminal maturation, including atypical initiator methionine-serine cleavage and proline acetylation, a modification not seen in other biological systems. We define a specialized pathway of two sequential aminopeptidases and an amino terminal acetyltransferase, dedicated to RbcL, that executes processing. This maturation is coupled to chaperone-assisted holoenzyme assembly, enhances activation by Rubisco activase, and shields the complex from degradation during senescence. Disruption of this pathway reduces Rubisco accumulation and catalytic competence, revealing an evolutionarily tailored mechanism integrating protein maturation, assembly, and stability of a central metabolic enzyme.
Source: Science Advances
Authors: Dong Xie, Jens S. Mühlenbeck, Patrick Schall, Jean-Baptiste Boyer, Cyril Dian, Laila Sago, Yuwei Wang, Lucile Jomat, Juergen Eirich, Frédéric Frottin, Iris Finkemeier, Bernhard Grimm, Carmela Giglione, Thierry Meinnel
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $4,500
Awards: G1230675998, Infrastructure Française de Protéomique, G155422806, Elucidating the multifaceted functions of protein acetyltransferases in plant stress response and regulation of metabolism., Idex Paris-Saclay, Ecole Universitaire de Recherche de Sciences des Plantes de Paris-Saclay, Die Funktion von cotranslationalen Nterminalen Modifikationen plastidenkodierter Proteine unter Stresseinfluss, G6720320153, Challenging the role of plastid cotranslational N-terminal modifications upon stress response, Exploring the Roles of Chloroplast GNATs: Acetylation as a Regulatory Mechanism in Photosynthesis and Senescence, G7958419288
OpenAlex ID: W7212039552