title: Genetic control of nucleolar size: An evolutionary perspective.
abstract: Exploiting a C. elegans mutant (ncl-1) exhibiting nucleolar abnormalities, we recently identified the let-7/ncl-1/fib-1 genetic cascade underlying proper rRNA abundance and nucleolar size. These 3 factors, let-7 (a miRNA), NCL-1 (a member of the TRIM-NHL family), and fibrillarin (a nucleolar methyltransferase), are evolutionarily conserved across metazoans. In this article, we provide several lines of bioinformatic evidence showing that human and Drosophila homologues of C. elegans NCL-1, TRIM-71 and Brat, respectively, likely act as translational suppressors of fibrillarin. Moreover, since their 3'-UTRs contain putative target sites, they may also be under the control of the let-7 miRNA. We hypothesize that let-7, TRIM and fibrillarin contribute activities in concert, and constitute a conserved network controlling nucleolar size in eukaryotes. We provide an in-depth literature review of various molecular pathways, including the let-7/ncl-1/fib-1 genetic cascade, implicated in the regulation of nucleolar size.
authors.affiliation: a Department of Biomedical Sciences, College of Medicine , Chang Gung University , TaoYuan , Taiwan.|b Graduate Institute of Biomedical Sciences , College of Medicine , Chang Gung University , TaoYuan , Taiwan.
authors.forename: Tian-Hsiang
authors.initials: TH
authors.lastname: Ma
authors.affiliation: a Department of Biomedical Sciences, College of Medicine , Chang Gung University , TaoYuan , Taiwan.|c Molecular Medicine Research Center , College of Medicine , Chang Gung University , TaoYuan , Taiwan.
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Lee
authors.affiliation: d Institute of Chemistry , Academia Sinica , Taipei , Taiwan.
authors.forename: Chi-Chang
authors.initials: CC
authors.lastname: Lee
authors.affiliation: a Department of Biomedical Sciences, College of Medicine , Chang Gung University , TaoYuan , Taiwan.|c Molecular Medicine Research Center , College of Medicine , Chang Gung University , TaoYuan , Taiwan.
authors.forename: Yung-Hsiang
authors.initials: YH
authors.lastname: Yi
authors.affiliation: e Graduate Institute of Microbiology , College of Medicine , National Taiwan University , Taipei , Taiwan.
authors.forename: Shih-Peng
authors.initials: SP
authors.lastname: Chan
authors.affiliation: a Department of Biomedical Sciences, College of Medicine , Chang Gung University , TaoYuan , Taiwan.|b Graduate Institute of Biomedical Sciences , College of Medicine , Chang Gung University , TaoYuan , Taiwan.|c Molecular Medicine Research Center , College of Medicine , Chang Gung University , TaoYuan , Taiwan.
authors.forename: Bertrand Chin-Ming
authors.initials: BC
authors.lastname: Tan
authors.affiliation: a Department of Biomedical Sciences, College of Medicine , Chang Gung University , TaoYuan , Taiwan.|b Graduate Institute of Biomedical Sciences , College of Medicine , Chang Gung University , TaoYuan , Taiwan.|c Molecular Medicine Research Center , College of Medicine , Chang Gung University , TaoYuan , Taiwan.
authors.forename: Szecheng J
authors.initials: SJ
authors.lastname: Lo
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D002466:Cell Nucleolus; D019143:Evolution, Molecular; D006801:Humans; D053141:Organelle Size / Q000235:genetics*
chemical_list: D029742:Caenorhabditis elegans Proteins
keywords: C. elegans; DAO-5/Nopp140/Nolc1; fibrillarin; genetic cascade; membrane-less organelle; ribosome biogenesis; translational suppression; tumor suppressor