title: Barley DNA-binding methionine aminopeptidase, which changes the localization from the nucleus to the cytoplasm by low temperature, is involved in freezing tolerance.
abstract: The polymerase chain reaction-based Mirror Orientation Selection (MOS) method was used to isolate low temperature-induced genes from cold-treated winter barley (Hordeum vulgare L. cv. Dongbori). MOS screening identified a novel methionine (Met) aminopeptidase (MAP) designated as HvMAP. The deduced HvMAP protein was determined to possess an aminopeptidase domain and a nuclear localization signal. An in vitro enzyme assay using recombinant HvMAP protein demonstrated MAP activity. The expression of this gene was induced by low temperature and abscisic acid treatment, and overexpression of this gene conferred stronger freezing tolerance to Arabidopsis transgenic plants as compared to wild-type plants. Interestingly, low temperature treatment changed the localization of HvMAP from the nucleus to the cytoplasm. These findings suggest that HvMAP is a novel MAP that functions in freezing tolerance by facilitating protein maturation.
authors.affiliation: School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Republic of Korea.
authors.forename: Hee-Jeong
authors.initials: HJ
authors.lastname: Jeong
authors.forename: Jeong Sheop
authors.initials: JS
authors.lastname: Shin
authors.forename: Sung Han
authors.initials: SH
authors.lastname: Ok
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000626:Aminopeptidases / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology; D015152:Blotting, Northern; D002467:Cell Nucleus / Q000378:metabolism*; D003080:Cold Temperature; D005615:Freezing; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D001467:Hordeum / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D063208:Methionyl Aminopeptidases; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D010940:Plant Proteins; D000040:Abscisic Acid; D000626:Aminopeptidases; D063208:Methionyl Aminopeptidases