title: SPAT-1/Bora acts with Polo-like kinase 1 to regulate PAR polarity and cell cycle progression.
abstract: During asymmetric cell division, cell polarity and cell cycle progression are tightly coordinated, yet mechanisms controlling both these events are poorly understood. Here we show that the Bora homologue SPAT-1 regulates both PAR polarity and cell cycle progression in C. elegans embryos. We find that, similarly to mammalian cells, SPAT-1 acts with PLK-1 and not with the mitotic kinase Aurora A (AIR-1), as shown in Drosophila. SPAT-1 binds to PLK-1, and depletion of SPAT-1 or PLK-1 leads to similar cell division defects in early embryos, which differ from the defects caused by depletion of AIR-1. Additionally, SPAT-1 and PLK-1 depletion causes impaired polarity with abnormal length of the anterior and posterior PAR domains, and partial plk-1(RNAi) or spat-1(RNAi), but not air-1(RNAi), can rescue the lethality of a par-2 mutant. SPAT-1 is enriched in posterior cells, and this enrichment depends on PAR polarity and PLK-1. Taken together, our data suggest a model in which SPAT-1 promotes the activity of PLK-1 to regulate both cell polarity and cell cycle timing during asymmetric cell division, providing a link between these two processes.
authors.affiliation: Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, 1 rue Michel Servet, Geneva 4, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Noatynska
authors.forename: Costanza
authors.initials: C
authors.lastname: Panbianco
authors.forename: Monica
authors.initials: M
authors.lastname: Gotta
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology* / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D016764:Cell Polarity; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D000097869:Polo-Like Kinase 1
chemical_list: D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D000097869:Polo-Like Kinase 1; C552693:SPAT-1 protein, C elegans; C087977:par-2 protein, C elegans