title: The Arabidopsis thaliana tandem zinc finger 1 (AtTZF1) protein in RNA binding and decay.
abstract: The Arabidopsis thaliana tandem zinc finger 1 (AtTZF1) protein is characterized by two tandem-arrayed CCCH-type zinc fingers. We have previously found that AtTZF1 affects hormone-mediated growth, stress and gene expression responses. While much has been learned at the genetic and physiological level, the molecular mechanisms underlying the effects of AtTZF1 on gene expression remain obscure. A human TZF protein, hTTP, is known to bind and trigger the degradation of mRNAs containing AU-rich elements (AREs) at the 3' untranslated regions. However, while the TZF motif of hTTP is characterized by C(X8)C(X5)C(X3)H-(X18)-C(X8)C(X5)C(X3)H, AtTZF1 contains an atypical motif of C(X7)C(X5)C(X3)H-(X16)-C(X5)C(X4)C(X3)H. Moreover, the TZF motif of AtTZF1 is preceded by an arginine-rich (RR) region that is unique to plants. Using fluorescence anisotropy and electrophoretic mobility shift binding assays, we have demonstrated that AtTZF1 binds to RNA molecules with specificity and the interaction is dependent on the presence of zinc. Compared with hTTP, in which TZF is solely responsible for RNA binding, both TZF and RR regions of AtTZF1 are required to achieve high-affinity RNA binding. Moreover, zinc finger integrity is vital for RNA binding. Using a plant protoplast transient expression analysis we have further revealed that AtTZF1 can trigger the decay of ARE-containing mRNAs in vivo. Taken together, our results support the notion that AtTZF1 is involved in RNA turnover.
authors.affiliation: Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH, 43210, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Qu
authors.forename: Shin Gene
authors.initials: SG
authors.lastname: Kang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Karin
authors.initials: K
authors.lastname: Musier-Forsyth
authors.forename: Jyan-Chyun
authors.initials: JC
authors.lastname: Jang
mesh_terms: D063307:AU Rich Elements; D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D005454:Fluorescence Polarization; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D020871:RNA Stability; D018749:RNA, Plant / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D051816:Tristetraprolin / Q000378:metabolism; D016335:Zinc Fingers
chemical_list: D029681:Arabidopsis Proteins; D018749:RNA, Plant; D011993:Recombinant Fusion Proteins; C548151:TZF1 protein, Arabidopsis; D014157:Transcription Factors; D051816:Tristetraprolin; C497552:ZFP36 protein, human; D005982:Glutathione Transferase
keywords: AU-rich elements; Arabidopsis thaliana; AtTZF1; RNA turnover; arginine-rich (RR) motif; protein-RNA interaction; tandem CCCH zinc finger (TZF) motif