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Palmitoylated importin α regulates mitotic spindle orientation through interaction with NuMA
Patrick James Sutton1, Natalie Mosqueda2, Christopher W Brownlee3
1Department of Pharmacological Sciences, Stony Brook University, Stony Brook, 11794, USA. Patrick.Sutton@stonybrook.edu.
EMBO Reports
|May 27, 2025
Summary
Palmitoylated importin alpha is crucial for orienting cell division, preventing microcephaly. Disrupting this process in Xenopus embryos caused developmental defects, highlighting importin alpha palmitoylation
Area of Science:
- Cell Biology
- Developmental Biology
- Neuroscience
Background:
- Cell division orientation is vital for tissue development and homeostasis.
- Mitotic spindle orientation relies on protein complexes at the cell cortex.
- Spindle misorientation in neuroblasts can lead to microcephaly.
Purpose of the Study:
- To investigate the role of importin alpha in mitotic spindle orientation.
- To determine the significance of importin alpha palmitoylation in this process.
Main Methods:
- Examined the localization of importin alpha and associated factors (e.g., NuMA) at the cell cortex.
- Studied the effects of abrogating importin alpha palmitoylation in Xenopus laevis embryos.
Main Results:
- Palmitoylated importin alpha localizes factors like NuMA to the cell cortex, crucial for spindle orientation.
- Abrogation of importin alpha palmitoylation in Xenopus embryos resulted in craniofacial defects, including smaller heads and brains.
- These defects are characteristic of spindle misorientation and microcephaly.
Conclusions:
- Importin alpha, specifically its palmitoylated form, plays a critical role in mitotic spindle orientation.
- Importin alpha palmitoylation is essential for normal craniofacial and brain development.
- These findings reveal a broader role for importin alpha palmitoylation in cellular processes.
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