title: Geminin is Essential to Prevent DNA Re-Replication-Dependent Apoptosis in Pluripotent Cells, but not in Differentiated Cells.
abstract: Geminin is a dual-function protein unique to multicellular animals with roles in modulating gene expression and preventing DNA re-replication. Here, we show that geminin is essential at the beginning of mammalian development to prevent DNA re-replication in pluripotent cells, exemplified by embryonic stem cells, as they undergo self-renewal and differentiation. Embryonic stem cells, embryonic fibroblasts, and immortalized fibroblasts were characterized before and after geminin was depleted either by gene ablation or siRNA. Depletion of geminin under conditions that promote either self-renewal or differentiation rapidly induced DNA re-replication, followed by DNA damage, then a DNA damage response, and finally apoptosis. Once differentiation had occurred, geminin was no longer essential for viability, although it continued to contribute to preventing DNA re-replication induced DNA damage. No relationship was detected between expression of geminin and genes associated with either pluripotency or differentiation. Thus, the primary role of geminin at the beginning of mammalian development is to prevent DNA re-replication-dependent apoptosis, a role previously believed essential only in cancer cells. These results suggest that regulation of gene expression by geminin occurs only after pluripotent cells differentiate into cells in which geminin is not essential for viability.
authors.affiliation: Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Yi-Yuan
authors.initials: YY
authors.lastname: Huang
authors.affiliation: Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Kotaro J
authors.initials: KJ
authors.lastname: Kaneko
authors.affiliation: Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Pan
authors.affiliation: Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Melvin L
authors.initials: ML
authors.lastname: DePamphilis
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D004261:DNA Replication / Q000502:physiology*; D053595:Embryonic Stem Cells / Q000502:physiology*; D064248:Geminin / Q000172:deficiency / Q000502:physiology*; D051379:Mice; D008822:Mice, Transgenic; D039904:Pluripotent Stem Cells / Q000502:physiology*
chemical_list: D064248:Geminin
keywords: Apoptosis; DNA re-replication; Embryonic fibroblasts; Embryonic stem cells; Geminin; Pluripotent