Speaker
Description
Rubisco is a unique catalyst involved in biological carbon dioxide fixation. It is also the most abundant protein on Earth which accumulation rises up to 50% the protein content of leaves. As a major storage protein, nitrogen recycling from Rubisco is essential during degradative processes such as plant senescence or starvation. In land plants, Rubisco functions as a large multi-subunit complex that requires specialized auxiliary factors for the proper assembly of its subunits, RbcL and RbcS. [1]. The catalytic activity of Rubisco depends on the carbamylation of a lysine residue in RbcL and is sustained by a chaperone known as Rubisco activase (Rca). In addition to carbamylation, RbcL was suggested to undergo a number of putative modifications which might impact its overall overall activity [2,3]. Among them, RbcL features a conserved N-terminus starting with an acetylated proline [2,4]. This type of N-terminal acetylation has not been reported in any other protein [5].
I will present data on the identification and characterization of enzymes responsible for completing the N-terminal processing of RbcL and possible function lying behind this remarkably conserved pathway of plants.
References
1. Hayer-Hartl & Hartl 2020 Trends Biochem Sci 45, 748.
2. Houtz et al. 2008 J Exp Bot 59, 1635.
3. Hartl et al. 2017 Mol Syst Biol 13, 949.
4. Meinnel & Giglione 2022 J Exp Bot 73, 6013.
5. Aksnes et al. 2016 Trends Biochem Sci 41, 746.
6. Aigner et al. 2017 Science 358, 1272.