Evolution of the modular, disordered stress proteins known as dehydrins

Abstract

Dehydrins, plant proteins that are upregulated during dehydration stress conditions, have modular sequences that can contain three conserved motifs (the Y-, S-, and K-segments). The presence and order of these motifs are used to classify dehydrins into one of five architectures: Kn, SKn, KnS, YnKn, and YnSKn, where the subscript n describes the number of copies of that motif. In this study, an architectural and phylogenetic analysis was performed on 426 dehydrin sequences that were identified in 53 angiosperm and 3 gymnosperm genomes. It was found that angiosperms contained all five architectures, while gymnosperms only contained Kn and SKn dehydrins. This suggests that the ancestral dehydrin in spermatophytes was either Kn or SKn, and the Y-segment containing dehydrins first arose in angiosperms. A high-level split between the YnSKn dehydrins from either the Kn or SKn dehydrins could not be confidently identified, however, two lower level architectural divisions appear to have occurred after different duplication events. The first likely occurred after a whole genome duplication, resulting in the duplication of a Y3SK2 dehydrin; the duplicate subsequently lost an S- and K- segment to become a Y3K1 dehydrin. The second split occurred after a tandem duplication of a Y1SK2 dehydrin, where the duplicate lost both the Y- and S- segment and gained four K-segments, resulting in a K6 dehydrin. We suggest that the newly arisen Y3K1 dehydrin is possibly on its way to pseudogenization, while the newly arisen K6 dehydrin developed a novel function in cold protection.

Conserved sequence motifs in the abiotic stress response protein late embryogenesis abundant 3

“…Genome-wide analysis of LEA proteins in a single species have been previously performed to evaluate common motifs, expression patterns, evolution, and predicted localization [11,[30][31][32][33][34][35] Multi-genome analyses on the dehydrin group resulted in a more rigorous and consistent motif description [36] and provided insight into their evolution [37]. However, to date there is a lack of targeted studies investigating other LEA groups, such as LEA3, across multiple plant species.…”

Effects of Exogenous Salicylic Acid on Drought Response and Characterization of Dehydrins in Impatiens walleriana

“…Dehydrins are composed of at least one family-defining K-segment, variable number of conserved Y-segments and a single S-segment, which are interspersed with regions that are not conserved and are generally termed φ-segments [ 18 , 20 ]. Lys-rich K-segment, present in all dehydrins, is usually [EKKGIMDKIKEKLPG], but none of its residues is absolutely conserved, so it is presented as [XKXGXX(D/E)KIK(D/E)KXPG] by consensus [ 20 ]. The K-segment is implicated in membrane binding [ 53 , 54 ].…”

“…Dehydrins belong to late embryogenesis abundant (LEA) proteins (group 2) and are commonly induced in response to drought and other abiotic stresses [ 8 , 18 ]. Experiments in vitro suggest that dehydrins can stabilize membranes, protect proteins from aggregation, cryoprotect enzymes, protect nucleic acids, scavenge ROS and can bind small ligands including water, ice crystals and metal ions, but these findings need the in vivo conformation [ 18 , 19 , 20 ]. Having mostly polar and charged residues, dehydrins lack defined secondary and tertiary structure, and are thus defined as intrinsically disordered proteins (IDPs).…”

Lysine, Lysine-Rich, Serine, and Serine-Rich Proteins: Link Between Metabolism, Development, and Abiotic Stress Tolerance and the Role of ncRNAs in Their Regulation

“…DHNs are group II LEA proteins and are widely distributed in bryophytes, gymnosperms, and angiosperms ( Yu et al, 2018 ), accumulate during embryogenesis and induced in vegetative tissues following exposure to diverse environmental stresses ( Battaglia et al, 2008 ). They are low molecular weight (ranging 9–200 kD), modular, intrinsically disordered proteins (IDPs), and lack well-defined three-dimensional structures ( Riley et al, 2019 ). But SbDHN5 (from Sorghum bicolor ) has been discovered as an ordered protein with phosphorylation sites ( Nagaraju et al, 2018 ).…”