Investigating the Functional Role of the Cysteine Residue in Dehydrin from the Arctic Mouse-Ear Chickweed <i>Cerastium arcticum</i>
Il-Sup Kim,
Woong Choi,
Ae Kyung Park,
Hyun Kim,
Jonghyeon Son,
Jun Hyuck Lee,
Seung Chul Shin,
T. Doohun Kim,
Han-Woo Kim
Affiliations
Il-Sup Kim
Advanced Bio-Resource R&D Center, Kyungpook National University, Daegu 41566, Korea
Woong Choi
Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Korea
Ae Kyung Park
Division of Bacterial Diseases, Center for Laboratory Control of Infectious Diseases, Korea Centers for Diseases Control and Prevention, Cheongju-si 28159, Korea
Hyun Kim
Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Korea
Jonghyeon Son
Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Korea
Jun Hyuck Lee
Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Korea
Seung Chul Shin
Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Korea
T. Doohun Kim
Department of Chemistry, Graduate School of General Studies, Sookmyung Women’s University, Seoul 04310, Korea
Han-Woo Kim
Research Unit of Cryogenic Novel Material, Korea Polar Research Institute, Incheon 21990, Korea
The stress-responsive, SK5 subclass, dehydrin gene, CaDHN, has been identified from the Arctic mouse-ear chickweed Cerastium arcticum. CaDHN contains an unusual single cysteine residue (Cys143), which can form intermolecular disulfide bonds. Mutational analysis and a redox experiment confirmed that the dimerization of CaDHN was the result of an intermolecular disulfide bond between the cysteine residues. The biochemical and physiological functions of the mutant C143A were also investigated by in vitro and in vivo assays using yeast cells, where it enhanced the scavenging of reactive oxygen species (ROS) by neutralizing hydrogen peroxide. Our results show that the cysteine residue in CaDHN helps to enhance C. arcticum tolerance to abiotic stress by regulating the dimerization of the intrinsically disordered CaDHN protein, which acts as a defense mechanism against extreme polar environments.
