title: Ube3a-ATS is an atypical RNA polymerase II transcript that represses the paternal expression of Ube3a.
abstract: The Angelman syndrome gene, UBE3A, is subject to genomic imprinting controlled by mechanisms that are only partially understood. Its antisense transcript, UBE3A-ATS, is also imprinted and hypothesized to suppress UBE3A in cis. In this research, we showed that the mouse antisense ortholog, Ube3a-ATS, was transcribed by RNA polymerase (RNAP) II. However, unlike typical protein-coding transcripts, Ube3a-ATS was not poly-adenylated and was localized exclusively in the nucleus. It was relatively unstable with a half-life of 4 h, shorter than most protein-coding RNAs tested. To understand the role of Ube3a-ATS in vivo, a mouse model with a 0.9-kb genomic deletion over the paternal Snrpn major promoter was studied. The mice showed partial activation of paternal Ube3a, with decreased expression of Ube3a-ATS but not any imprinting defects in the Prader-Willi syndrome/Angelman syndrome region. A novel cell culture model was also generated with a transcriptional termination cassette inserted downstream of Ube3a on the paternal chromosome to reduce Ube3a-ATS transcription. In neuronally differentiated embryonic stem (ES) cells, paternal Ube3a was found to be expressed at a high level, comparable with that of the maternal allele. To further characterize the antisense RNA, a strand-specific microarray was performed. Ube3a-ATS was detectable across the entire locus of Ube3a and extended beyond the transcriptional start site of Ube3a. In summary, we conclude that Ube3a-ATS is an atypical RNAPII transcript that represses Ube3a on the paternal chromosome. These results suggest that the repression of human UBE3A-ATS may activate the expression of UBE3A from the paternal chromosome, providing a potential therapeutic strategy for patients with Angelman syndrome.
authors.affiliation: Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Linyan
authors.initials: L
authors.lastname: Meng
authors.forename: Richard E
authors.initials: RE
authors.lastname: Person
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Beaudet
mesh_terms: D017204:Angelman Syndrome / Q000235:genetics / Q000473:pathology / Q000628:therapy; D000818:Animals; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000378:metabolism; D005260:Female; D018392:Genomic Imprinting; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000378:metabolism; D026723:Polyadenylation; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II; D016372:RNA, Antisense / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D044767:Ubiquitin-Protein Ligases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D055517:snRNP Core Proteins / Q000235:genetics
chemical_list: D016372:RNA, Antisense; D055517:snRNP Core Proteins; C502429:Ube3a protein, mouse; D044767:Ubiquitin-Protein Ligases; D012319:RNA Polymerase II