Exploring the Diversity of the Thioredoxin Systems in Cyanobacteria

Cyanobacteria evolved the ability to perform oxygenic photosynthesis using light energy to reduce CO2 from electrons extracted from water and form nutrients. These organisms also devel-oped light-dependent redox regulation through the Trx system, formed by thioredoxins (Trxs) and thioredoxin reducta...

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Detalles Bibliográficos
Autores: Mallén Ponce, Manuel J., Huertas Romera, María José, Florencio Bellido, Francisco Javier
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/132194
Acceso en línea:https://hdl.handle.net/11441/132194
https://doi.org/10.3390/antiox11040654
Access Level:acceso abierto
Palabra clave:Cyanobacteria
Evolution
Metabolism
Oxidative stress
Redox regulation
Thioredoxin
Thioredoxin reductase
Descripción
Sumario:Cyanobacteria evolved the ability to perform oxygenic photosynthesis using light energy to reduce CO2 from electrons extracted from water and form nutrients. These organisms also devel-oped light-dependent redox regulation through the Trx system, formed by thioredoxins (Trxs) and thioredoxin reductases (TRs). Trxs are thiol-disulfide oxidoreductases that serve as reducing sub-strates for target enzymes involved in numerous processes such as photosynthetic CO2 fixation and stress responses. We focus on the evolutionary diversity of Trx systems in cyanobacteria and discuss their phylogenetic relationships. The study shows that most cyanobacteria contain at least one copy of each identified Trx, and TrxA is the only one present in all genomes analyzed. Ferredoxin thiore-doxin reductase (FTR) is present in all groups except Gloeobacter and Prochlorococcus, where there is a ferredoxin flavin-thioredoxin reductase (FFTR). Our data suggest that both TRs may have coex-isted in ancestral cyanobacteria together with other evolutionarily related proteins such as NTRC or DDOR, probably used against oxidative stress. Phylogenetic studies indicate that they have different evolutionary histories. As cyanobacteria diversified to occupy new habitats, some of these proteins were gradually lost in some groups. Finally, we also review the physiological relevance of redox regulation in cyanobacteria through the study of target enzymes.