title: A G-quadruplex structure at the 5' end of the H19 coding region regulates H19 transcription.
abstract: The H19 gene, one of the best known imprinted genes, encodes a long non-coding RNA that regulates cell proliferation and differentiation. H19 RNA is widely expressed in embryonic tissues, but its expression is restricted in only a few tissues after birth. However, regulation of H19 gene expression remains poorly understood outside the context of genomic imprinting. Here we identified evolutionarily conserved guanine (G)-rich repeated motifs at the 5' end of the H19 coding region that are consistent with theoretically deduced G-quadruplex sequences. Circular dichroism spectroscopy and electrophoretic mobility shift assays with G-quadruplex-specific ligands revealed that the G-rich motif, located immediately downstream of the transcription start site (TSS), forms a G-quadruplex structure in vitro. By using a series of mutant forms of H19 harboring deletion or G-to-A substitutions, we found that the H19-G-quadruplex regulates H19 gene expression. We further showed that transcription factors Sp1 and E2F1 were associated with the H19-G-quadruplex to either suppress or promote the H19 transcription, respectively. Moreover, H19 expression during differentiation of mouse embryonic stem cells appears to be regulated by a genomic H19 G-quadruplex. These results demonstrate that the G-quadruplex structure immediately downstream of the TSS functions as a novel regulatory element for H19 gene expression.
authors.affiliation: Department of Biosystems Science, Institute for Frontier Life and Medical Science, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.|Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Mitsuko
authors.initials: M
authors.lastname: Fukuhara
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo 184-8588, Japan.
authors.forename: Yue
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo 184-8588, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nagasawa
authors.affiliation: Department of Biosystems Science, Institute for Frontier Life and Medical Science, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.|Department of Mammalian Regulatory Network, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Toyoshima
mesh_terms: D000818:Animals; D002942:Circular Dichroism; D019175:DNA Methylation / Q000235:genetics; D050687:E2F1 Transcription Factor / Q000235:genetics; D054856:G-Quadruplexes; D005786:Gene Expression Regulation / Q000235:genetics; D018392:Genomic Imprinting / Q000235:genetics*; D006147:Guanine / Q000378:metabolism; D006801:Humans; D051379:Mice; D059372:Nucleotide Motifs / Q000235:genetics*; D016366:Open Reading Frames / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D062085:RNA, Long Noncoding / Q000235:genetics*; D017384:Sequence Deletion / Q000235:genetics; D016329:Sp1 Transcription Factor / Q000235:genetics; D024363:Transcription Initiation Site
chemical_list: D050687:E2F1 Transcription Factor; C493754:E2f1 protein, mouse; C094335:H19 long non-coding RNA; D062085:RNA, Long Noncoding; D016329:Sp1 Transcription Factor; D006147:Guanine