title: Reptin regulates pluripotency of embryonic stem cells and somatic cell reprogramming through Oct4-dependent mechanism.
abstract: Oct4 has been implicated in regulation of pluripotency in embryonic stem cells (ESCs) and reprogramming of somatic cells into induced pluripotent stem cells. However, the molecular mechanisms involved in Oct4-dependent regulation of pluripotency and reprogramming have not been clear. To gain insight into the mechanism of regulation of Oct4-mediated self-renewal of ESCs and reprogramming of somatic cells, we attempted to identify Oct4-binding proteins using affinity purification and mass spectrometry. We identified Reptin, a key component of ATP-dependent chromatin remodeling complexes, as an Oct4-binding protein. Depletion of endogenous Reptin using lentiviral short hairpin RNA (shRNA) led to a decrease in the number and size of alkaline phosphatase-positive colonies of mouse ESCs. In addition, shRNA-mediated silencing of Reptin resulted in decreased expression of pluripotency-specific marker genes, including Oct4, Sox2, Nanog, and SSEA-1. Results of the Oct4 reporter assay showed synergism between Oct4 and Reptin, and depletion of endogenous Reptin abolished Oct4 transcriptional activity. Results of a chromatin immunoprecipitation assay showed the overlapping interaction of Reptin and Oct4 to CR4 in the Oct4 enhancer in ESCs. Knockdown of Reptin using shRNA suppressed the reprogramming of mouse embryonic fibroblasts to induced pluripotent stem cells, whereas overexpression of Reptin resulted in enhanced efficiency of induced pluripotent stem cell generation. These results strongly suggest that Reptin plays a key role in maintaining the pluripotency of ESCs and in establishing the pluripotency during reprogramming of somatic cells by regulation of Oct4-mediated gene regulation.
authors.affiliation: Department of Physiology, School of Medicine, Pusan National University, Yangsan, Gyeongsangnam-do, Republic of Korea.
authors.forename: Eun Kyoung
authors.initials: EK
authors.lastname: Do
authors.forename: Hyo Cheon
authors.initials: HC
authors.lastname: Cheon
authors.forename: Il Ho
authors.initials: IH
authors.lastname: Jang
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Choi
authors.forename: Soon Chul
authors.initials: SC
authors.lastname: Heo
authors.forename: Kyung Taek
authors.initials: KT
authors.lastname: Kang
authors.forename: Kwang Hee
authors.initials: KH
authors.lastname: Bae
authors.forename: Yee Sook
authors.initials: YS
authors.lastname: Cho
authors.forename: Jeong Kon
authors.initials: JK
authors.lastname: Seo
authors.forename: Jong Hyuk
authors.initials: JH
authors.lastname: Yoon
authors.forename: Taehoon G
authors.initials: TG
authors.lastname: Lee
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D065150:Cellular Reprogramming / Q000502:physiology; D004265:DNA Helicases / Q000378:metabolism*; D051379:Mice; D000066450:Mouse Embryonic Stem Cells / Q000378:metabolism*; D050814:Octamer Transcription Factor-3 / Q000378:metabolism*; D039904:Pluripotent Stem Cells / Q000378:metabolism*
chemical_list: D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; C525850:TIP49 protein, mouse; D004265:DNA Helicases
keywords: Embryonic stem cells; Induced pluripotent stem; Oct4; Reprogramming; Reptin