Faculty Opinions recommendation of Aurora-A kinase is required for centrosome maturation in Caenorhabditis elegans.

Regulation of mitosis in time and space is critical for proper cell division. We conducted an RNA interference–based modifier screen to identify novel regulators of mitosis in Caenorhabditis elegans embryos. Of particular interest, this screen revealed that the Nup205 nucleoporin NPP-3 can negatively modulate the timing of mitotic onset. Furthermore, we discovered that NPP-3 and nucleoporins that are associated with it are lost from the nuclear envelope (NE) in the vicinity of centrosomes at the onset of mitosis. We demonstrate that centrosomes are both necessary and sufficient for NPP-3 local loss, which also requires the activity of the Aurora-A kinase AIR-1. Our findings taken together support a model in which centrosomes and AIR-1 promote timely onset of mitosis by locally removing NPP-3 and associated nucleoporins from the NE.

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Aurora-A kinase is required for centrosome maturation in Caenorhabditis elegans

The Journal of Cell Biology ◽

10.1083/jcb.200108051 ◽

2001 ◽

Vol 155 (7) ◽

pp. 1109-1116 ◽

Cited By ~ 292

Author(s):

Eva Hannak ◽

Matthew Kirkham ◽

Anthony A. Hyman ◽

Karen Oegema

Keyword(s):

Caenorhabditis Elegans ◽

Fluorescence Intensity ◽

Maturation Process ◽

Aurora A Kinase ◽

Aurora A ◽

Wild Type ◽

C Elegans ◽

Nuclear Envelope Breakdown ◽

Pericentriolar Material

Centrosomes mature as cells enter mitosis, accumulating γ-tubulin and other pericentriolar material (PCM) components. This occurs concomitant with an increase in the number of centrosomally organized microtubules (MTs). Here, we use RNA-mediated interference (RNAi) to examine the role of the aurora-A kinase, AIR-1, during centrosome maturation in Caenorhabditis elegans. In air-1(RNAi) embryos, centrosomes separate normally, an event that occurs before maturation in C. elegans. After nuclear envelope breakdown, the separated centrosomes collapse together, and spindle assembly fails. In mitotic air-1(RNAi) embryos, centrosomal α-tubulin fluorescence intensity accumulates to only 40% of wild-type levels, suggesting a defect in the maturation process. Consistent with this hypothesis, we find that AIR-1 is required for the increase in centrosomal γ-tubulin and two other PCM components, ZYG-9 and CeGrip, as embryos enter mitosis. Furthermore, the AIR-1–dependent increase in centrosomal γ-tubulin does not require MTs. These results suggest that aurora-A kinases are required to execute a MT-independent pathway for the recruitment of PCM during centrosome maturation.

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Faculty Opinions recommendation of Aurora-A kinase is required for centrosome maturation in Caenorhabditis elegans.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1005016.58556 ◽

2002 ◽

Author(s):

Bruce Bowerman

Keyword(s):

Caenorhabditis Elegans ◽

Aurora A Kinase ◽

Aurora A

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Aurora A depletion reveals centrosome-independent polarization mechanism in Caenorhabditis elegans

eLife ◽

10.7554/elife.44552 ◽

2019 ◽

Vol 8 ◽

Cited By ~ 18

Author(s):

Kerstin Klinkert ◽

Nicolas Levernier ◽

Peter Gross ◽

Christian Gentili ◽

Lukas von Tobel ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Symmetry Breaking ◽

Break Symmetry ◽

Dependent Manner ◽

Aurora A Kinase ◽

Aurora A ◽

Physical Description ◽

C Elegans ◽

Actin Cortex ◽

Polarization Mechanism

How living systems break symmetry in an organized manner is a fundamental question in biology. In wild-type Caenorhabditis elegans zygotes, symmetry breaking during anterior-posterior axis specification is guided by centrosomes, resulting in anterior-directed cortical flows and a single posterior PAR-2 domain. We uncover that C. elegans zygotes depleted of the Aurora A kinase AIR-1 or lacking centrosomes entirely usually establish two posterior PAR-2 domains, one at each pole. We demonstrate that AIR-1 prevents symmetry breaking early in the cell cycle, whereas centrosomal AIR-1 instructs polarity initiation thereafter. Using triangular microfabricated chambers, we establish that bipolarity of air-1(RNAi) embryos occurs effectively in a cell-shape and curvature-dependent manner. Furthermore, we develop an integrated physical description of symmetry breaking, wherein local PAR-2-dependent weakening of the actin cortex, together with mutual inhibition of anterior and posterior PAR proteins, provides a mechanism for spontaneous symmetry breaking without centrosomes.

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Caenorhabditis elegans Aurora A kinase is required for the formation of spindle microtubules in female meiosis

Molecular Biology of the Cell ◽

10.1091/mbc.e15-05-0258 ◽

2015 ◽

Vol 26 (23) ◽

pp. 4187-4196 ◽

Cited By ~ 10

Author(s):

Eisuke Sumiyoshi ◽

Yuma Fukata ◽

Satoshi Namai ◽

Asako Sugimoto

Keyword(s):

Caenorhabditis Elegans ◽

Kinase Activity ◽

Active Form ◽

Meiotic Spindle ◽

Aurora A Kinase ◽

Aurora A ◽

Female Meiosis ◽

Germinal Vesicle Breakdown ◽

Meiotic Spindles ◽

Spindle Microtubules

In many animals, female meiotic spindles are assembled in the absence of centrosomes, the major microtubule (MT)-organizing centers. How MTs are formed and organized into meiotic spindles is poorly understood. Here we report that, in Caenorhabditis elegans, Aurora A kinase/AIR-1 is required for the formation of spindle microtubules during female meiosis. When AIR-1 was depleted or its kinase activity was inhibited in C. elegans oocytes, although MTs were formed around chromosomes at germinal vesicle breakdown (GVBD), they were decreased during meiotic prometaphase and failed to form a bipolar spindle, and chromosomes were not separated into two masses. Whereas AIR-1 protein was detected on and around meiotic spindles, its kinase-active form was concentrated on chromosomes at prometaphase and on interchromosomal MTs during late anaphase and telophase. We also found that AIR-1 is involved in the assembly of short, dynamic MTs in the meiotic cytoplasm, and these short MTs were actively incorporated into meiotic spindles. Collectively our results suggest that, after GVBD, the kinase activity of AIR-1 is continuously required for the assembly and/or stabilization of female meiotic spindle MTs.

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Caenorhabditis elegans Aurora A kinase AIR-1 is required for postembryonic cell divisions and germline development

genesis ◽

10.1002/gene.10157 ◽

2002 ◽

Vol 34 (4) ◽

pp. 244-250 ◽

Cited By ~ 8

Author(s):

Tokiko Furuta ◽

David L. Baillie ◽

Jill M. Schumacher

Keyword(s):

Caenorhabditis Elegans ◽

Aurora A Kinase ◽

Aurora A ◽

Germline Development ◽

Cell Divisions

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Centrosome Aurora A gradient ensures single polarity axis in C. elegans embryos

Biochemical Society Transactions ◽

10.1042/bst20200298 ◽

2020 ◽

Vol 48 (3) ◽

pp. 1243-1253 ◽

Cited By ~ 1

Author(s):

Sukriti Kapoor ◽

Sachin Kotak

Keyword(s):

Symmetry Breaking ◽

Cell Fate ◽

Cell Cortex ◽

Axis Formation ◽

Aurora A Kinase ◽

Aurora A ◽

C Elegans ◽

Cell Embryo ◽

Polarity Establishment

Cellular asymmetries are vital for generating cell fate diversity during development and in stem cells. In the newly fertilized Caenorhabditis elegans embryo, centrosomes are responsible for polarity establishment, i.e. anterior–posterior body axis formation. The signal for polarity originates from the centrosomes and is transmitted to the cell cortex, where it disassembles the actomyosin network. This event leads to symmetry breaking and the establishment of distinct domains of evolutionarily conserved PAR proteins. However, the identity of an essential component that localizes to the centrosomes and promotes symmetry breaking was unknown. Recent work has uncovered that the loss of Aurora A kinase (AIR-1 in C. elegans and hereafter referred to as Aurora A) in the one-cell embryo disrupts stereotypical actomyosin-based cortical flows that occur at the time of polarity establishment. This misregulation of actomyosin flow dynamics results in the occurrence of two polarity axes. Notably, the role of Aurora A in ensuring a single polarity axis is independent of its well-established function in centrosome maturation. The mechanism by which Aurora A directs symmetry breaking is likely through direct regulation of Rho-dependent contractility. In this mini-review, we will discuss the unconventional role of Aurora A kinase in polarity establishment in C. elegans embryos and propose a refined model of centrosome-dependent symmetry breaking.

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