Sirtuins: not only animal proteins

Abstract

Sirtuins are proteins belonging to the group of NADH-dependent deacetylase and mono-ADP-ribosyltransferase enzymes. Sirtuins have been discovered for the first time in yeasts, subsequent studies have shown their presence in bacteria, plants and animals. These enzymes are frequently called longevity enzymes due to the fact that they are part of genetic apparatus involved in aging control. In animals, sirtuins are key regulators of cell defense in response to stress caused by many metabolic processes; they are also involved in the regulation of cell division, metabolism, gene silencing and genetic material repair as well as apoptosis. Thus far, only several well-known research teams have been studying plant proteins resembling animal sirtuins. Considering the fact how essential functions sirtuins play in other organisms, it is extremely interesting to understand their role in plants, especially that the knowledge about them is still limited. It is believed that the function of sirtuins in Arabidopsis thaliana is associated with mitochondrial energy metabolism. Possibly they may also control the synthesis of auxins or proteins involved in their transport, or they may be responsible for regulating cellular response to auxin action. In rice, sirtuins are necessary for the protection against genomic instability and cell damage that guarantee their growth. They also take part in a defensive response against Pseudomonas syringae. They may also be involved in the ripening of fruits.Moreover, their functions are associated with photosynthetic activity and aging of leaves.

Canonical and Noncanonical Actions of Arabidopsis Histone Deacetylases in Ribosomal RNA Processing

“…Like HD2C and HD2B (this study), SIRT7 plays an important role in ribosome biogenesis by regulating rRNAs processing (Chen et al, 2016a). Compared with seven mammalian SIRTs (Haigis and Guarente, 2006), there are only two SIRT proteins in Arabidopsis, rice (Oryza sativa), and maize (Zea mays) (Szućko, 2016). These observations raise an interesting hypothesis that HD2 proteins may have evolved to partially complement the missing SIRT proteins in plants.…”

Genome‐wide identification, phylogeny, and gene duplication of the epigenetic regulators in Fagaceae

“…However, three SRTs have been also described in soybean and in the lower plant Marchantia polymorpha (Zheng, 2020 ). Moreover, these proteins exist in higher numbers in other organisms, associated with different cellular locations (Szućko, 2016 ). Contrastingly, HDA14 duplications, restricted to Quercus genera, seem to have occurred more recently as the similarity between sequences is higher (Table S7 ) and all lie in the same chromosome (Tables S4 and S5 ) suggesting a proximal duplication event (Qiao et al, 2019 ).…”

Redox status of the plant cell determines epigenetic modifications under abiotic stress conditions and during developmental processes

“…Unlike in animal systems, the number of sirtuins reported in plant systems is low [93] . Two SIRT genes each are reported from Arabidopsis ( AtSRT1 and AtSRT2 ) and rice ( OsSRT1 and OsSRT2 ) [94] , and one from durum wheat ( WhSRT2 ) [95] .…”