title: PAR-6 is a conserved PDZ domain-containing protein that colocalizes with PAR-3 in Caenorhabditis elegans embryos.
abstract: The par genes are required to establish polarity in the Caenorhabditis elegans embryo. Mutations in two of these genes, par-3 and par-6, exhibit similar phenotypes. A third gene, pkc-3, gives a similar phenotype when the protein is depleted by RNA interference. PAR-3 and PKC-3 protein are colocalized to the anterior periphery of asymmetrically dividing cells of the germline lineage and the peripheral localizations of both proteins depends upon the activity of par-6. Here we report the molecular cloning of par-6 and the immunolocalization of PAR-6 protein. We found that par-6 encodes a PDZ-domain-containing protein and has homologues in mammals and flies. Moreover, we discovered that PAR-6 colocalizes with PAR-3 and that par-3 and pkc-3 activity are required for the peripheral localization of PAR-6. The localization of both PAR-3 and PAR-6 proteins is affected identically by mutations in the par-2, par-4 and par-5 genes. The co-dependence of PAR-3, PAR-6 and PKC-3 for peripheral localization and the overlap in their distributions lead us to propose that they act in a protein complex.
authors.affiliation: Section of Genetics and Development, Cornell University, Ithaca, NY 14853, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Hung
authors.forename: K J
authors.initials: KJ
authors.lastname: Kemphues
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D051017:Apoptosis Regulatory Proteins; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000235:genetics; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004331:Drosophila melanogaster / Q000235:genetics; D004625:Embryo, Nonmammalian; D020224:Expressed Sequence Tags; D018507:Gene Expression Regulation, Developmental; D015801:Helminth Proteins / Q000235:genetics* / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D008969:Molecular Sequence Data; D011493:Protein Kinase C / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D011506:Proteins; D017386:Sequence Homology, Amino Acid; D015053:Zygote
chemical_list: D051017:Apoptosis Regulatory Proteins; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D015801:Helminth Proteins; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; C087977:par-2 protein, C elegans; C512642:par-6 protein, C elegans; C101296:prostate apoptosis response-4 protein; C097238:PAR-3 protein, C elegans; D017346:Protein Serine-Threonine Kinases; C115015:PKC-3 protein; D011493:Protein Kinase C