title: FBF represses the Cip/Kip cell-cycle inhibitor CKI-2 to promote self-renewal of germline stem cells in C. elegans.
abstract: Although the decision between stem cell self-renewal and differentiation has been linked to cell-cycle modifications, our understanding of cell-cycle regulation in stem cells is very limited. Here, we report that FBF/Pumilio, a conserved RNA-binding protein, promotes self-renewal of germline stem cells by repressing CKI-2(Cip/Kip), a Cyclin E/Cdk2 inhibitor. We have previously shown that repression of CYE-1 (Cyclin E) by another RNA-binding protein, GLD-1/Quaking, promotes germ cell differentiation. Together, these findings suggest that a post-transcriptional regulatory circuit involving FBF and GLD-1 controls the self-renewal versus differentiation decision in the germline by promoting high CYE-1/CDK-2 activity in stem cells, and inhibiting CYE-1/CDK-2 activity in differentiating cells.
authors.affiliation: Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
authors.forename: Irene
authors.initials: I
authors.lastname: Kalchhauser
authors.forename: Brian M
authors.initials: BM
authors.lastname: Farley
authors.forename: Sandra
authors.initials: S
authors.lastname: Pauli
authors.forename: Sean P
authors.initials: SP
authors.lastname: Ryder
authors.forename: Rafal
authors.initials: R
authors.lastname: Ciosk
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D002453:Cell Cycle; D002478:Cells, Cultured; D050756:Cyclin-Dependent Kinase Inhibitor Proteins / Q000037:antagonists & inhibitors*; D005786:Gene Expression Regulation; D016601:RNA-Binding Proteins / Q000378:metabolism*; D013234:Stem Cells / Q000502:physiology*
chemical_list: D029742:Caenorhabditis elegans Proteins; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D016601:RNA-Binding Proteins; C412838:cki-2 protein, C elegans; C109286:fem-3-binding protein, C elegans