title: Comparative analysis of Arabidopsis zinc finger-containing glycine-rich RNA-binding proteins during cold adaptation.
abstract: Among the three zinc finger-containing glycine-rich RNA-binding proteins, named AtRZ-1a, AtRZ-1b, and AtRZ-1c, in the Arabidopsis thaliana genome, AtRZ-1a has previously been shown to enhance cold and freezing tolerance in Arabidopsis. Here, we determined and compared the functional roles of AtRZ-1b and AtRZ-1c in Arabidopsis and Escherichia coli under cold stress conditions. AtRZ-1b, but not AtRZ-1c, successfully complemented the cold sensitivity of E. coli BX04 mutant cells lacking four cold shock proteins. Domain deletion and site-directed mutagenesis showed that the zinc finger motif of AtRZ-1b is important for its complementation ability, and that the truncated N- and C-terminal domains of AtRZ-1b and AtRZ-1c harbor the complementation ability. Despite an increase in transcript levels of AtRZ-1b and AtRZ-1c under cold stress, overexpression or loss-of-function mutations did not affect seed germination or seedling growth of Arabidopsis under cold stress conditions. AtRZ-1b and AtRZ-1c proteins, being localized to the nucleus, have been shown to bind non-specifically to RNA sequences in vitro, in comparison to AtRZ-1a that is localized to both the nucleus and the cytoplasm and binds preferentially to G- or U-rich RNA sequences. Taken together, these results demonstrate that the three AtRZ-1 family members showing different cellular localization and characteristic nucleic acid-binding property have a potential to contribute differently to the enhancement of cold tolerance in Arabidopsis and E. coli.
authors.affiliation: Department of Plant Biotechnology, Agricultural Plant Stress Research Center and Biotechnology Research Institute, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Won Yong
authors.initials: WY
authors.lastname: Kim
authors.forename: Joo Yeol
authors.initials: JY
authors.lastname: Kim
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Jung
authors.forename: Seung Han
authors.initials: SH
authors.lastname: Oh
authors.forename: Yeon Soo
authors.initials: YS
authors.lastname: Han
authors.forename: Hunseung
authors.initials: H
authors.lastname: Kang
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D057773:Cold Shock Proteins and Peptides / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D003593:Cytoplasm / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D017343:Genes, Plant; D016296:Mutagenesis; D009154:Mutation; D009711:Nucleotides / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D036226:Seedlings / Q000254:growth & development; D012639:Seeds / Q000254:growth & development; D013312:Stress, Physiological / Q000235:genetics; D016335:Zinc Fingers / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D057773:Cold Shock Proteins and Peptides; D009711:Nucleotides; D016601:RNA-Binding Proteins; D012313:RNA