title: Characterization of calnexin in soybean roots and hypocotyls under osmotic stress.
abstract: Calnexin is an endoplasmic reticulum-localized molecular chaperone protein which is involved in folding and quality control of proteins. To evaluate the expression of calnexin in soybean seedlings under osmotic stress, immunoblot analysis was performed using a total membrane protein fraction. Calnexin constantly accumulated at an early growth stage of soybean under normal growth conditions. Expression of this protein decreased in 14-day-old soybean roots when treated with 10% polyethylene glycol for 2 days. Other abiotic stresses such as drought, salinity, cold as well as abscisic acid treatment, similarly reduced accumulation of calnexin and this reduction was correlated with reduction in root length in soybean seedlings under abiotic stresses. When compared between soybean and rice, calnexin expression was not changed in rice under abiotic stresses. Using Flag-tagged calnexin, a 70 kDa heat shock cognate protein was identified as an interacting protein. These results suggest that osmotic or other abiotic stresses highly reduce accumulation of the calnexin protein in developing soybean roots. It is also suggested that calnexin interacts with a 70 kDa heat shock cognate protein and probably functions as molecular chaperone in soybean.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba 305-8572, Japan.
authors.forename: Mohammad-Zaman
authors.initials: MZ
authors.lastname: Nouri
authors.forename: Susumu
authors.initials: S
authors.lastname: Hiraga
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yanagawa
authors.forename: Yukari
authors.initials: Y
authors.lastname: Sunohara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Setsuko
authors.initials: S
authors.lastname: Komatsu
mesh_terms: D000040:Abscisic Acid / Q000009:adverse effects; D000222:Adaptation, Physiological; D037281:Calnexin / Q000378:metabolism*; D003080:Cold Temperature; D055864:Droughts; D006360:Heat-Shock Proteins / Q000378:metabolism; D018546:Hypocotyl / Q000254:growth & development / Q000378:metabolism*; D018832:Molecular Chaperones / Q000378:metabolism; D012275:Oryza / Q000378:metabolism; D009995:Osmosis; D010940:Plant Proteins / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism*; D011092:Polyethylene Glycols; D054712:Salinity; D013025:Glycine max / Q000254:growth & development / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D010940:Plant Proteins; D037281:Calnexin; D011092:Polyethylene Glycols; D000040:Abscisic Acid