title: Direct and positive regulation of Caenorhabditis elegans bed-3 by PRDM1/BLIMP1 ortholog BLMP-1.
abstract: Caenorhabditis elegans BLMP-1 is the homolog of mammalian PRDM1/BLIMP1 transcriptional repressor and a component of the heterochronic pathway regulating developmental timing. We found that BLMP-1 positively and directly regulates the bed-3 gene required for vulval cell division and molting. blmp-1 mutation or RNAi reduces bed-3 reporter expression and causes phenotype similar to bed-3 mutations. We mapped an enhancer element responsible for bed-3 expression in the vulva and the hypodermis to a 200 bp region in the third intron. Using EMSA, we identified BLMP-1 binding sites within this region. Mutating these sites abolished both in vitro BLMP-1 binding and in vivo enhancer activity. Thus, BLMP-1 directly and positively regulates bed-3 transcription, connecting the heterochronic pathway to regulation of vulval cell division and molting. Recently, C. elegans blmp-1 was found to act as a transcriptional repressor. Thus, C. elegans BLMP-1 acts as a transcriptional activator or a repressor depending on the context.
authors.affiliation: Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore.
authors.forename: Jin
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore.
authors.forename: Hei Tung
authors.initials: HT
authors.lastname: Fong
authors.affiliation: Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore.
authors.forename: Zhengyang
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore.
authors.forename: Jason Wei Han
authors.initials: JW
authors.lastname: Tan
authors.affiliation: Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore. Electronic address: bchti@nus.edu.sg.
authors.forename: Takao
authors.initials: T
authors.lastname: Inoue
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation / Q000502:physiology*; D007438:Introns; D014157:Transcription Factors / Q000235:genetics*; D019076:Transgenes
chemical_list: C548502:BED-3 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D014157:Transcription Factors
keywords: C. elegans; Cell division; Gene expression; Heterochronic pathway; Organogenesis; PRDM1