title: Helinoto, a Helitron2 transposon from the icefish Chionodraco hamatus, contains a region with three deubiquitinase-like domains that exhibit transcriptional activity.
abstract: Transposable elements have accompanied the evolution of the eukaryotic genome for millions of years. The recently discovered Helitron order (class II, subclass 2 single-strand DNA transposons) is common in eukaryotes and seems to play a highly active role in genome reshuffling. This study provides novel insights into the characteristics of Helinoto, a helitron isolated in the genome of the Antarctic fish Chionodraco hamatus. In particular, investigation of the structure of its 5' and 3' ends, which are involved in the transposition process, enabled identification of the characteristic motifs of the Helitron2 group. Moreover, identification of a deubiquitinating protease domain in the region upstream two consecutive OTU domains extended and strengthened the "deubiquitinase" character of the N-terminal portion of Helinoto. Finally, Helinoto transcriptional activity was detected in several C. hamatus tissues. Taken together, these data are particularly intriguing because they document high transcription levels for genes involved in ubiquitination, which ensures protein homeostasis in the extreme Antarctic environment.
authors.affiliation: Department of Biological Science, "Federico II" University, Via Cinthia, 21, 80126 Napoli, Italy. Electronic address: teresa.capriglione@unina.it.
authors.forename: Teresa
authors.initials: T
authors.lastname: Capriglione
authors.affiliation: Department of Biological Science, "Federico II" University, Via Cinthia, 21, 80126 Napoli, Italy. Electronic address: sofia.depaolo@unina.it.
authors.forename: Sofia
authors.initials: S
authors.lastname: De Paolo
authors.affiliation: Institute of Biosciences and BioResources, National Research Council (CNR-IBBR), Via P. Castellino 111, 80131 Napoli, Italy. Electronic address: ennio.cocca@ibbr.cnr.it.
authors.forename: Ennio
authors.initials: E
authors.lastname: Cocca
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004251:DNA Transposable Elements / Q000235:genetics*; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010473:Perciformes / Q000235:genetics*; D017434:Protein Structure, Tertiary; D012313:RNA / Q000032:analysis / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*; D064570:Ubiquitin-Specific Proteases / Q000235:genetics* / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D012313:RNA; D064570:Ubiquitin-Specific Proteases
keywords: Antarctic fish; DNA transposon; Deubiquitinase; Helitron; USP domain