title: The Caenorhabditis elegans par-5 gene encodes a 14-3-3 protein required for cellular asymmetry in the early embryo.
abstract: The establishment of anterior-posterior polarity in the Caenorhabditis elegans embryo requires the activity of the maternally expressed par genes. We report the identification and analysis of a new par gene, par-5. We show that par-5 is required for asynchrony and asymmetry in the first embryonic cell divisions, normal pseudocleavage, normal cleavage spindle orientation at the two-cell stage, and localization of P granules and MEX-5 during the first and subsequent cell cycles. Furthermore, par-5 activity is required in the first cell cycle for the asymmetric cortical localization of PAR-1 and PAR-2 to the posterior, and PAR-3, PAR-6, and PKC-3 to the anterior. When PAR-5 is reduced by mutation or by RNA interference, these proteins spread around the cortex of the one-cell embryo and partially overlap. We have shown by sequence analysis of par-5 mutants and by RNA interference that the par-5 gene is the same as the ftt-1 gene, and encodes a 14-3-3 protein. The PAR-5 14-3-3 protein is present in gonads, oocytes, and early embryos, but is not asymmetrically distributed. Our analysis indicates that the par-5 14-3-3 gene plays a crucial role in the early events leading to polarization of the C. elegans zygote.
authors.affiliation: Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Diane G
authors.initials: DG
authors.lastname: Morton
authors.forename: Diane C
authors.initials: DC
authors.lastname: Shakes
authors.forename: Staci
authors.initials: S
authors.lastname: Nugent
authors.forename: Daryl
authors.initials: D
authors.lastname: Dichoso
authors.forename: Wenfu
authors.initials: W
authors.lastname: Wang
authors.forename: Andy
authors.initials: A
authors.lastname: Golden
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Kemphues
mesh_terms: D048948:14-3-3 Proteins; D000595:Amino Acid Sequence; D000818:Animals; D019521:Body Patterning / Q000235:genetics; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism; D002455:Cell Division; D018509:DNA, Helminth / Q000235:genetics; D005260:Female; D005298:Fertility / Q000235:genetics; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D018510:RNA, Helminth / Q000235:genetics; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics* / Q000378:metabolism; D015053:Zygote / Q000166:cytology
chemical_list: D048948:14-3-3 Proteins; D029742:Caenorhabditis elegans Proteins; D018509:DNA, Helminth; D015801:Helminth Proteins; D018510:RNA, Helminth; C106207:par-5 protein, C elegans; D014446:Tyrosine 3-Monooxygenase