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Updated: Jun 3, 2026
Live Imaging of Drosophila Larval Neuroblasts
Published on: July 7, 2014
Drosophila Ajuba is not an Aurora-A activator but is required to maintain Aurora-A at the centrosome
Dora Sabino1, Nicholas H Brown, Renata Basto
1Compartimentation et Dynamique Cellulaires, CNRS, UMR144 Paris F-75248, France.
Abstract:
The LIM-domain protein Ajuba localizes at sites of epithelial cell-cell adhesion and has also been implicated in the activation of Aurora-A (Aur-A). Despite the expected importance of Ajuba, Ajuba-deficient mice are viable, which has been attributed to functional redundancy with the related LIM-domain protein LIMD1. To gain insights into the function of Ajuba, we investigated its role in Drosophila, where a single gene (jub) encodes a protein closely related to Ajuba and LIMD1. We identified a key function in neural stem cells, where Jub localizes to the centrosome. In these cells, mutation in jub leads to centrosome separation defects and aberrant mitotic spindles, which is a phenotype similar to that of aur-A mutants. We show that in jub mutants Aur-A activity is not perturbed, but that Aur-A recruitment and maintenance at the centrosome is affected. As a consequence the active kinase is displaced from the centrosome. On the basis of our studies in Drosophila neuroblasts, we propose that a key function of Ajuba, in these cells, is to maintain active Aur-A at the centrosome during mitosis.
Insights
The LIM-domain protein Ajuba is crucial for maintaining active Aurora-A kinase at the centrosome during mitosis in Drosophila neural stem cells, preventing spindle defects. This research clarifies Ajuba
Area of Science:
- Cell Biology
- Developmental Biology
- Genetics
Background:
- The LIM-domain protein Ajuba is involved in cell adhesion and Aurora-A kinase (Aur-A) activation.
- Ajuba-deficient mice are viable, suggesting functional redundancy with LIMD1.
- Investigating Ajuba's role in Drosophila provides insights into its conserved functions.
Purpose of the Study:
- To elucidate the function of the Ajuba-related protein Jub in Drosophila.
- To understand Jub's role in neural stem cell division and centrosome regulation.
- To determine the relationship between Jub and Aurora-A kinase during mitosis.
Main Methods:
- Utilized Drosophila as a model organism to study the jub gene.
- Examined the localization of Jub in neural stem cells.
- Analyzed mitotic phenotypes in jub mutants, including centrosome separation and spindle formation.
- Assessed Aurora-A kinase activity and localization in jub mutants.
Main Results:
- Jub localizes to the centrosome in Drosophila neural stem cells.
- Loss of Jub function leads to centrosome separation defects and aberrant mitotic spindles.
- Aurora-A kinase activity is not affected in jub mutants.
- Recruitment and maintenance of Aurora-A at the centrosome are impaired in jub mutants, leading to kinase displacement.
Conclusions:
- Jub plays a critical role in maintaining Aurora-A kinase at the centrosome during mitosis in Drosophila neuroblasts.
- Proper localization of active Aurora-A by Jub is essential for correct centrosome function and mitotic spindle organization.
- This study highlights a conserved function of Ajuba family proteins in regulating centrosome-associated kinases.
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