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Measurement of Microtubule Dynamics by Spinning Disk Microscopy in Monopolar Mitotic Spindles
Published on: November 15, 2019
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Centrosomal ALIX regulates mitotic spindle orientation by modulating astral microtubule dynamics
Lene Malerød1,2, Roland Le Borgne3,4, Anette Lie-Jensen1,2
1Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.
The EMBO Journal
|June 3, 2018
Summary
The adaptor protein ALIX (ALG-2-interacting protein X) is crucial for mitotic spindle orientation. It ensures proper cell division by promoting microtubule formation and stability in various cell types.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Mitotic spindle (MS) orientation is vital for cell division but its regulation is not fully understood.
- The multifunctional adaptor protein ALIX (ALG-2-interacting protein X) is known for its role in cytokinesis.
Purpose of the Study:
- To investigate the novel role of ALIX in regulating mitotic spindle orientation.
- To elucidate the molecular mechanisms by which ALIX influences MS orientation.
Main Methods:
- Investigated ALIX recruitment to pericentriolar material (PCM) in Drosophila and human cells.
- Analyzed the impact of ALIX depletion on astral microtubule (MT) formation and MS orientation.
- Examined the interaction of ALIX with DSpd-2/Cep192 and MAP1S.
Main Results:
- ALIX is recruited to the PCM via DSpd-2/Cep192 and promotes gamma-tubulin accumulation for efficient astral MT nucleation.
- ALIX enhances MT stability by recruiting MAP1S, crucial for stabilizing newly formed MTs.
- ALIX-deprived cells exhibit defective astral MT formation and abnormal MS orientation in both asymmetric and symmetric divisions.
Conclusions:
- ALIX plays a novel, evolutionarily conserved role in regulating mitotic spindle orientation.
- ALIX ensures robust MS orientation by promoting astral MT formation and stability during cell division.
- This finding expands the known functions of ALIX beyond cytokinesis.
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