title: Cold shock protein 1 chaperones mRNAs during translation in Arabidopsis thaliana.
abstract: RNA binding proteins (RBPs) function post-transcriptionally to fine-tune gene regulation. Arabidopsis thaliana has four Gly-rich, zinc finger-containing RBPs called cold shock proteins 1-4 (CSP1-CSP4), that possess an evolutionary conserved cold shock domain. Here, we determined that CSP1 associates with polyribosomes (polysomes) via an RNA-mediated interaction. Both the abundance and polysomal co-fractionation of CSP1 was enhanced in the cold (4°C), but did not influence global levels of polysomes, which were minimally perturbed by above freezing cold temperatures. Using a polyclonal antiserum, CSP1 was co-immunopurified with several hundred transcripts from rosettes of plants cultivated at 23°C or transferred to 4°C for 12 h. CSP1-associated mRNAs were characterized by G+C-rich 5' untranslated regions and gene ontologies related to cellular respiration, mRNA binding and translation. The majority of the CSP1-associated mRNAs were constitutively expressed and stable in the cold. CSP1 abundance was correlated with improved translation of ribosomal protein mRNAs during cold stress and improved maintenance of homeostasis and translation of mRNAs under water-deficit stress. In summary, CSP1 selectively chaperones mRNAs, providing translational enhancement during stress.
authors.affiliation: Department of Botany and Plant Sciences, Center for Plant Cell Biology, University of California, Riverside, California 92521, USA.
authors.forename: Piyada
authors.initials: P
authors.lastname: Juntawong
authors.forename: Reed
authors.initials: R
authors.lastname: Sorenson
authors.forename: Julia
authors.initials: J
authors.lastname: Bailey-Serres
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D057773:Cold Shock Proteins and Peptides / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D003600:Cytosol / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D055864:Droughts; D015870:Gene Expression; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D030821:Plants, Genetically Modified; D011132:Polyribosomes / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics; D013312:Stress, Physiological; D020506:Untranslated Regions / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C517509:CSDP1 protein, Arabidopsis; D057773:Cold Shock Proteins and Peptides; D004268:DNA-Binding Proteins; D018832:Molecular Chaperones; D012333:RNA, Messenger; D018749:RNA, Plant; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; D020506:Untranslated Regions