Paternally expressed gene 3 (Peg3) is an imprinted gene that encodes a protein with twelve C2H2 zinc finger domains. Thus, PEG3 protein is predicted to serve as a transcription factor that may regulate other gene expression. Chromatin immunoprecipitation (ChIP) experiment revealed a list of genes that are bound by PEG3, supporting PEG3 is a DNA-binding protein. Genome wide expression analysis using wild type and Peg3 knockout mouse models further suggested that a large number of genes were up-regulated in Peg3 knockout model, including imprinted genes and some tissue-specific genes, suggesting that PEG3 may mainly function as a repressor for its downstream genes.
It is well known that most imprinted genes are organized into clusters (imprinted domains) to share cis-acting elements which can regulate imprinted gene expression. However, in Peg3 imprinted domain, one of my studies suggested that two oppositely imprinted genes in Peg3 imprinted domain could interact through their gene products rather than shared cis regulatory elements. According to the results, paternally expressed Peg3 controls maternally expressed Zim1 as a trans factor. Removing PEG3 resulted in elevated expression of Zim1, thus PEG3 should serve as a repressor for Zim1. ChIP experiment further suggested that PEG3 might repress Zim1 expression through SETDB1/KAP1-driven H3K9me3 mechanism.
Subsequent ChIP-seq analysis using mouse embryonic fibroblast (MEF) cells further identified 16 target genes as PEG3 downstream genes. Interestingly, most of these genes showed high level of expression in oocyte, in which Peg3 is not expressed. Furthermore, qRT-PCR analysis confirmed that PEG3 mainly functions as a repressor for these downstream genes. In addition, electromobility shift assay (EMSA) and the luciferase reporter assay further demonstrated that PEG3 can directly bind to H19-ICR to repress H19 expression.
Overall, the research presented in this dissertation advances our understanding of the repression function of PEG3 protein and its potential tumor suppressor function linked to its downstream genes.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-06272016-122920 |
| Date | 11 July 2016 |
| Creators | Ye, An |
| Contributors | Kim, Joomyeong, Donze, David, Grove, Anne, Byerly, Gary |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-06272016-122920/ |
| Rights | restricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
Page generated in 0.0075 seconds