title: lin-35/Rb and ubc-18, an E2 ubiquitin-conjugating enzyme, function redundantly to control pharyngeal morphogenesis in C. elegans.
abstract: The retinoblastoma gene product has been implicated in the regulation of multiple cellular and developmental processes, including a well-defined role in the control of cell cycle progression. The Caenorhabditis elegans retinoblastoma protein homolog, LIN-35, is also a key regulator of cell cycle entry and, as shown by studies of synthetic multivulval genes, plays an important role in the determination of vulval cell fates. We demonstrate an additional and unexpected function for lin-35 in organ morphogenesis. Using a genetic approach to isolate lin-35 synthetic-lethal mutations, we have identified redundant roles for lin-35 and ubc-18, a gene that encodes an E2 ubiquitin-conjugating enzyme closely related to human UBCH7. lin-35 and ubc-18 cooperate to control one or more steps during pharyngeal morphogenesis. Based on genetic and phenotypic analyses, this role for lin-35 in pharyngeal morphogenesis appears to be distinct from its cell cycle-related functions. lin-35 and ubc-18 may act in concert to regulate the levels of one or more critical targets during C. elegans development.
authors.affiliation: Department of Molecular Biology, University of Wyoming, PO Box 3944, Laramie, WY 82071-3944, USA. davidfay@uwyo.edu
authors.forename: David S
authors.initials: DS
authors.lastname: Fay
authors.forename: Edward
authors.initials: E
authors.lastname: Large
authors.forename: Min
authors.initials: M
authors.lastname: Han
authors.forename: Monica
authors.initials: M
authors.lastname: Darland
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D019070:Cell Lineage; D003001:Cloning, Molecular; D003360:Cosmids; D003433:Crosses, Genetic; D005821:Genetic Techniques; D016678:Genome; D006579:Heterozygote; D006801:Humans; D008025:Ligases / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D010614:Pharynx / Q000196:embryology; D010641:Phenotype; D034622:RNA Interference; D012097:Repressor Proteins / Q000235:genetics* / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D025801:Ubiquitin / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; D012097:Repressor Proteins; D025801:Ubiquitin; C116485:lin-35 protein, C elegans; D008025:Ligases; C476242:Ubc-18 protein, C elegans