Ube3a-ATS is an atypical RNA polymerase II transcript that represses the paternal expression of Ube3a

• Published in: Human molecular genetics Vol. 21; no. 13; pp. 3001 - 3012
• Main Authors: Meng, Linyan, Person, Richard E., Beaudet, Arthur L.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.07.2012
• Subjects: Angelman Syndrome - genetics; Angelman Syndrome - pathology; Angelman Syndrome - therapy; Animals; Biological and medical sciences; Cells, Cultured; Embryonic Stem Cells - metabolism; Female; Fundamental and applied biological sciences. Psychology; Genetics of eukaryotes. Biological and molecular evolution; Genomic Imprinting; Humans; Male; Mice; Mice, Inbred C57BL; Molecular and cellular biology; Neurons - metabolism; Polyadenylation; Promoter Regions, Genetic; RNA Polymerase II; RNA, Antisense - genetics; RNA, Antisense - metabolism; snRNP Core Proteins - genetics; Transcription, Genetic; Ubiquitin-Protein Ligases - biosynthesis; Ubiquitin-Protein Ligases - genetics; Ubiquitin-Protein Ligases - metabolism; Messenger RNA; Gene; Genetics; Atypical; Repression; Gene expression; Father; RNA polymerase II
• ISSN: 0964-6906; 1460-2083; 1460-2083
• DOI: 10.1093/hmg/dds130

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.