title: Paternally expressed Peg3 controls maternally expressed Zim1 as a trans factor.
abstract: The expression of two adjacent imprinted genes, Peg3 and Zim1, is inversely correlated: down-regulation of Peg3 coinciding with up-regulation of Zim1. The current study characterized this inverse correlation using a mutant allele targeting Peg3. According to the results, the mutation on the paternal allele of Peg3 resulted in a dramatic increase in the transcription levels of the maternal allele of Zim1, suggesting the involvement of unknown trans factors in this trans-allelic event. Subsequent ChIP experiments revealed that the protein encoded by Peg3 itself binds to the zinc finger exon of Zim1, which is modified with the repression mark H3K9me3. Interestingly, the levels of H3K9me3 on Zim1 are also reduced in the mutant cells lacking the protein PEG3, suggesting potential roles for PEG3 in establishing H3K9me3 on Zim1. Reintroducing PEG3 into the mutant cell restored down-regulation of Zim1, confirming the predicted repressor role for Peg3 on Zim1. Overall, these results demonstrated that paternally expressed Peg3 controls maternally expressed Zim1 as a trans factor. The current study also provides the first case for the trans-allelic interaction of two oppositely imprinted genes through their gene products.
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States of America.
authors.forename: An
authors.initials: A
authors.lastname: Ye
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States of America.
authors.forename: Hongzhi
authors.initials: H
authors.lastname: He
authors.affiliation: Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, United States of America.
authors.forename: Joomyeong
authors.initials: J
authors.lastname: Kim
mesh_terms: D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics; D002478:Cells, Cultured; D004268:DNA-Binding Proteins; D015536:Down-Regulation; D018507:Gene Expression Regulation, Developmental; D055786:Gene Knockout Techniques; D018392:Genomic Imprinting / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics; D006657:Histones / Q000378:metabolism; D051741:Kruppel-Like Transcription Factors / Q000096:biosynthesis* / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000235:genetics*; D015854:Up-Regulation; D016335:Zinc Fingers / Q000235:genetics
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D006657:Histones; D051741:Kruppel-Like Transcription Factors; D009419:Nerve Tissue Proteins; C097901:Peg3 protein, mouse; C119426:Zim1 protein, mouse; D049452:Green Fluorescent Proteins