Helinoto, a Helitron2 transposon from the icefish Chionodraco hamatus, contains a region with three deubiquitinase-like domains that exhibit transcriptional activity

• Published in: Comparative Biochemistry and Physiology Part D: Genomics and Proteomics
• Main Authors: CAPRIGLIONE, TERESA, DE PAOLO, SOFIA, Ennio Cocca
• Other Authors: Capriglione, Teresa, DE PAOLO, Sofia, Ennio, Cocca
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2014
• Subjects: Antarctic; Antarc*; Icefish
• Online Access: http://hdl.handle.net/11588/583044; https://doi.org/10.1016/j.cbd.2014.07.004

Transposable elements have accompanied the evolution of the eukaryotic genome for millions of 26 years. The recently discovered Helitron order (class II, subclass 2 single-strand DNA transposons) 27 is common in eukaryotes and seems to play a highly active role in genome reshuffling. This study 28 provides novel insights into the characteristics of Helinoto, a helitron isolated in the genome of the 29 Antarctic fish Chionodraco hamatus. In particular, investigation of the structure of its 5‘ and 3' 30 ends, which are involved in the transposition process, enabled identification of the characteristic 31 motifs of the Helitron2 group. Moreover, identification of a deubiquitinating protease domain in the 32 region upstream two consecutive OTU domains extended and strengthened the ―deubiquitinase‖ 33 character of the N-terminal portion of Helinoto. Finally, Helinoto transcriptional activity was 34 detected in several C. hamatus tissues. Taken together, these data are particularly intriguing because 35 they document high transcription levels for genes involved in ubiquitination, which ensures protein 36 homeostasis in the extreme Antarctic environment.