Biochemical characterization of the Arabidopsis KS-type dehydrin protein, whose gene expression is constitutively abundant rather than stress dependent

Abstract

Dehydrins are known as plant stress-responsive genes. Arabidopsis thaliana has 10 dehydrin genes. Among them, one of the highly expressed genes is a KS-type dehydrin (At1g54410). However, the gene product, which is a histidine-rich dehydrin whose molecular mass is 11 kDa (AtHIRD11), has not been studied. Thus, we report the biochemical characterization of the AtHIRD11 protein.Although the AtHIRD11 protein was detected in all organs of Arabidopsis, the bolting stem and the flower showed higher accumulation than the other organs, with the AtHIRD11 protein detected in the cambial zone of the stem vasculature. Most of the AtHIRD11 protein was found to be a bound form. The bound AtHIRD11 was solubilized by 1 M NaCl solution. The extracted AtHIRD11 was retained in immobilized metal-affinity chromatography, and eluted by an imidazole gradient. The native AtHIRD11 prepared from Arabidopsis was partially phosphorylated, but further phosphorylated by casein kinase 2 in vitro. Metal-binding assays indicated that Zn 2? may be the best metal for AtHIRD11 binding. These results suggest that AtHIRD11 is a metal-binding dehydrin that shows a house-keeping expression in Arabidopsis.

A KS-type dehydrin and its related domains reduce Cu-promoted radical generation and the histidine residues contribute to the radical-reducing activities

“…A recombinant AtHIRD11 protein was produced by a method reported previously (Hara et al, 2011). In brief, the open reading frame (ORF) of AtHIRD11 was inserted into the pET-30 Escherichia coli expression system (Novagen, WI, USA).…”

“…Dehydrins have been detected mainly in and/or near the vasculature (Godoy et al, 1994; Danyluk et al, 1998; Bravo et al, 1999; Nylander et al, 2001, Hara et al, 2011). Studies using transgenics and mutants have reported the relationship between dehydrin expression and stress tolerance in plants.…”

“…The Ricinus communis KS-type dehydrin ITP was identified as a metal transporter that moves through the phloem of young plants (Krüger et al, 2002). The Arabidopsis KS-type dehydrin AtHIRD11 (At1g54410), which accumulated in the cambial zone of the vasculature, also bound metals (Hara et al, 2011). (ii) The KS-type dehydrins are the shortest subfamily in terms of length (~100 amino acids) and therefore this type has a simple domain constitution, suggesting that, if the KS-type dehydrins can control ROS generation, the domains that are related to the control can be identified with comparative ease.…”

Expression of CdDHN4, a Novel YSK2-Type Dehydrin Gene from Bermudagrass, Responses to Drought Stress through the ABA-Dependent Signal Pathway

“…Generally, these proteins are hydrophilic proteins that contain three conserved motifs: the K, Y, and S segments (Rorat, 2006; Eriksson et al, 2011; Hara et al, 2011). The K segment is similar in sequence to EKKGIMDKIKEKLPG, which is a common feature of all dehydrins (DHNs) and a Lys- rich motif that forms an α-helix in the C-terminus that may participate in interaction with membranes and proteins (Allagulova et al, 2003; Koag et al, 2009; Hughes et al, 2013).…”

Transcriptome Profile in Response to Frost Tolerance in Eucalyptus globulus

“…It has been previously reported that DHN1 and DHN10 from E. globulus increase their transcript level in response to CA (Fernández et al 2012a, b). DHN10, a KS-type DHN, has been reported as a metal-binding dehydrin (Asghar et al 1994;Krüger et al 2002;Rorat 2006;Xu et al 2008;Hara et al 2011), suggesting that it can stabilize the transition metals by binding them, protecting organelles and enzymes under abiotic stress, and indirectly protecting the membrane, where the strength of ROS-reducing activities can be determined by the histidine contents (Rorat 2006) and the length of the peptides (Hara et al 2013). Keller et al (2013) reported a high representation of LEA/dehydrin in the cold transcriptome of E. gunnii, representing one of the main mechanisms of macromolecules and membrane protection, which may explain most of the hardening in this species.…”