Jurado Flores, AnaDelgado Requerey, VictorGálvez Ramírez, AliciaPuerto Galán, LeonorPérez Ruiz, Juan ManuelCejudo Fernández, Francisco Javier2020-11-192020-11-192020Jurado Flores, A., Delgado Requerey, V., Gálvez Ramírez, A., Puerto Galán, L., Pérez Ruiz, J.M. y Cejudo Fernández, F.J. (2020). Exploring the Functional Relationship between y-Type Thioredoxins and 2-Cys Peroxiredoxins in Arabidopsis Chloroplasts. Antioxidants, 9 (11), 1-18.2076-3921https://hdl.handle.net/11441/102731Thioredoxins (Trxs) are small, ubiquitous enzymes that catalyze disulphide–dithiol interchange in target enzymes. The large set of chloroplast Trxs, including f, m, x and y subtypes, use reducing equivalents fueled by photoreduced ferredoxin (Fdx) for fine-tuning photosynthetic performance and metabolism through the control of the activity of redox-sensitive proteins. Although biochemical analyses suggested functional diversity of chloroplast Trxs, genetic studies have established that deficiency in a particular Trx subtype has subtle phenotypic e ects, leading to the proposal that the Trx isoforms are functionally redundant. In addition, chloroplasts contain an NADPH-dependent Trx reductase with a joint Trx domain, termed NTRC. Interestingly, Arabidopsis mutants combining the deficiencies of x- or f-type Trxs and NTRC display very severe growth inhibition phenotypes, which are partially rescued by decreased levels of 2-Cys peroxiredoxins (Prxs). These findings indicate that the reducing capacity of Trxs f and x is modulated by the redox balance of 2-Cys Prxs, which is controlled by NTRC. In this study, we explored whether NTRC acts as a master regulator of the pool of chloroplast Trxs by analyzing its functional relationship with Trxs y. While Trx y interacts with 2-Cys Prxs in vitro and in planta, the analysis of Arabidopsis mutants devoid of NTRC and Trxs y suggests that Trxs y have only a minor e ect, if any, on the redox state of 2-Cys Prxs.application/pdf18 p.engAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/2-Cys peroxiredoxinThioredoxin yNTRCThioredoxin xRedox regulationStress responsePhotosynthesisChloroplastinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccesshttps://doi.org/10.3390/antiox9111072