title: UNC-84 localizes to the nuclear envelope and is required for nuclear migration and anchoring during C. elegans development.
abstract: Nuclear migrations are essential for metazoan development. Two nuclear migrations that occur during C. elegans development require the function of the unc-84 gene. unc-84 mutants are also defective in the anchoring of nuclei within the hypodermal syncytium and in the migrations of the two distal tip cells of the gonad. Complementation analyses of 17 unc-84 alleles defined two genetically separable functions. Both functions are required for nuclear and distal tip cell migrations, but only one is required for nuclear anchorage. The DNA lesions associated with these 17 mutations indicate that the two genetically defined functions correspond to two distinct regions of the UNC-84 protein. The UNC-84 protein has a predicted transmembrane domain and a C-terminal region with similarity to the S. pombe spindle pole body protein Sad1 and to two predicted mammalian proteins. Analysis of a green fluorescent protein reporter indicated that UNC-84 is widely expressed and localized to the nuclear envelope. We propose that UNC-84 functions to facilitate a nuclear-centrosomal interaction required for nuclear migration and anchorage.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular, Cellular and Developmental Biology, University of Colorado at Boulder, Boulder CO 80309-0347, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Malone
authors.forename: W D
authors.initials: WD
authors.lastname: Fixsen
authors.forename: H R
authors.initials: HR
authors.lastname: Horvitz
authors.forename: M
authors.initials: M
authors.lastname: Han
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development*; D029742:Caenorhabditis elegans Proteins; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D005816:Genetic Complementation Test; D015801:Helminth Proteins / Q000235:genetics* / Q000378:metabolism*; D007814:Larva / Q000166:cytology / Q000235:genetics / Q000254:growth & development; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D009685:Nuclear Envelope / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; C120560:Unc-84 protein, C elegans