title: The extended AT-hook is a novel RNA binding motif.
abstract: The AT-hook has been defined as a DNA binding peptide motif that contains a glycine-arginine-proline (G-R-P) tripeptide core flanked by basic amino acids. Recent reports documented variations in the sequence of AT-hooks and revealed RNA binding activity of some canonical AT-hooks, suggesting a higher structural and functional variability of this protein domain than previously anticipated. Here we describe the discovery and characterization of the extended AT-hook peptide motif (eAT-hook), in which basic amino acids appear symmetrical mainly at a distance of 12-15 amino acids from the G-R-P core. We identified 80 human and 60 mouse eAT-hook proteins and biochemically characterized the eAT-hooks of Tip5/BAZ2A, PTOV1 and GPBP1. Microscale thermophoresis and electrophoretic mobility shift assays reveal the nucleic acid binding features of this peptide motif, and show that eAT-hooks bind RNA with one order of magnitude higher affinity than DNA. In addition, cellular localization studies suggest a role for the N-terminal eAT-hook of PTOV1 in nucleocytoplasmic shuttling. In summary, our findings classify the eAT-hook as a novel nucleic acid binding motif, which potentially mediates various RNA-dependent cellular processes.
authors.affiliation: a Biochemistry Center Regensburg ; University of Regensburg ; Regensburg , Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Filarsky
authors.forename: Karina
authors.initials: K
authors.lastname: Zillner
authors.forename: Ingrid
authors.initials: I
authors.lastname: Araya
authors.forename: Ana
authors.initials: A
authors.lastname: Villar-Garea
authors.forename: Rainer
authors.initials: R
authors.lastname: Merkl
authors.forename: Gernot
authors.initials: G
authors.lastname: Längst
authors.forename: Attila
authors.initials: A
authors.lastname: Németh
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D001667:Binding, Competitive; D014408:Biomarkers, Tumor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D045325:HCT116 Cells; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009690:Nucleic Acid Conformation; D059372:Nucleotide Motifs / Q000235:genetics*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012313:RNA / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000092468:Bromodomain Containing Proteins; D048868:Adaptor Proteins, Signal Transducing
chemical_list: D014408:Biomarkers, Tumor; D002868:Chromosomal Proteins, Non-Histone; D004247:DNA; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D012313:RNA; C436708:BAZ2A protein, human; D000092468:Bromodomain Containing Proteins; C425183:PTOV1 protein, human; D048868:Adaptor Proteins, Signal Transducing
keywords: AKNA–AT-hook-containing transcription factor; AT-hook; Brg1–Brahma related gene 1; CaATL1–Capsicum annuum AT-hook-Like gene 1; Dot1L–Dot1 [Disrupter of telomere silencing protein 1]-like; GPBP1; GPBP1–GC-rich Promoter Binding Protein 1; HMG–high mobility group; LEDGF/p75–Lens epithelium-derived growth factor 75; MeCP2–Methyl-CpG-binding protein 2; Med25–Mediator complex subunit 25; PSR/JMJD6–Phosphatidylserine receptor–Jmj-domain containing protein D6; PTOV1; PTOV1–Prostate Tumor Overexpressed 1; RACK1–receptor of protein C kinase 1; RNA-binding domain; TAF1–TATA-binding protein-associated factor 1; TdIF1–Terminal deoxynucleotidyltransferase-interacting factor 1; Tip5; Tip5–TTF-I interacting protein 5; VL1–Vascular protein family Vasculin-like 1; eAT-hook–extended AT-hook; lncRNA–long non-coding RNA; microscale thermophoresis; protein-RNA interaction; rDNA En–rDNA enhancer; rDNA IGS–rDNA intergenic spacer; snRNA–small nuclear RNA