title: LIP-1 phosphatase controls the extent of germline proliferation in Caenorhabditis elegans.
abstract: Caenorhabditis elegans germline cells are maintained in an undifferentiated and mitotically dividing state by Notch signaling and the FBF (for fem-3 binding factor) RNA-binding protein. Here, we report that the LIP-1 phosphatase, a proposed homolog of mitogen-activated protein (MAP) kinase phosphatases, is required for the normal extent of germline proliferation, and that lip-1 controls germline proliferation by regulating MAP kinase activity. In wild-type germ lines, LIP-1 protein is present in the proximal third of the mitotic region, consistent with its effect on germline proliferation. We provide evidence that lip-1 expression in the germline mitotic region is controlled by a combination of GLP-1/Notch signaling and FBF repression. Unexpectedly, FBF controls the accumulation of lip-1 mRNA, and therefore is likely to control its stability or 3'-end formation. In a sensitized mutant background, LIP-1 can function as a pivotal regulator of the decision between proliferation and differentiation. The control of germline proliferation by LIP-1 has intriguing parallels with the control of stem cells and progenitor cells in vertebrates.
authors.affiliation: Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53706, USA.
authors.forename: Myon-Hee
authors.initials: MH
authors.lastname: Lee
authors.forename: Brad
authors.initials: B
authors.lastname: Hook
authors.forename: Liana B
authors.initials: LB
authors.lastname: Lamont
authors.forename: Marvin
authors.initials: M
authors.lastname: Wickens
authors.forename: Judith
authors.initials: J
authors.lastname: Kimble
mesh_terms: D020413:3' Untranslated Regions / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000276:immunology; D017173:Caenorhabditis elegans / Q000201:enzymology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism*; D049109:Cell Proliferation; D047369:Chromatin Immunoprecipitation; D004268:DNA-Binding Proteins / Q000276:immunology; D018507:Gene Expression Regulation, Developmental; D005854:Germ Cells / Q000201:enzymology / Q000254:growth & development*; D019950:Mitogen-Activated Protein Kinase 1; D008938:Mitosis; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D017027:Protein Tyrosine Phosphatases / Q000235:genetics* / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000276:immunology; D014157:Transcription Factors
chemical_list: D020413:3' Untranslated Regions; D000906:Antibodies; D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C409224:SEL-8 protein, C elegans; D015534:Trans-Activators; D014157:Transcription Factors; C109286:fem-3-binding protein, C elegans; D017346:Protein Serine-Threonine Kinases; D019950:Mitogen-Activated Protein Kinase 1; C085697:mpk-1 protein, C elegans; C421904:lip-1 protein, C elegans; D017027:Protein Tyrosine Phosphatases