Surreal illustration of cell division highlighting SPICE1 and Aurora kinases.

Decoding Cell Division: How SPICE1 and Aurora Kinases Ensure Accurate Chromosome Segregation

Avery Sinclair in Science & Nature August 2025 • 4 min read.

"Unlocking the secrets of mitotic regulation through computational biology and kinase substrate identification"

Cell division, or mitosis, is a fundamental process for life, ensuring growth, repair, and reproduction. This process depends on the accurate segregation of chromosomes, orchestrated by a complex interplay of proteins and enzymes. Mitotic kinases, a small group of enzymes, drive this precise choreography by phosphorylating hundreds of proteins. Errors in this process can lead to chromosomal instability, a hallmark of cancer and other developmental disorders.

Among the key players in mitosis are the Aurora kinases, a family of serine/threonine kinases crucial for maintaining genomic stability. These kinases, particularly Aurora A and B, control various mitotic events, from spindle assembly to chromosome condensation. Understanding how Aurora kinases function requires identifying their downstream targets and the mechanisms by which they regulate these targets.

Recent research has focused on identifying novel Aurora kinase substrates using a computational approach that combines phosphorylation site clustering, protein localization, protein structure, and species conservation data. One particularly promising substrate identified through this method is SPICE1 (Spindle and Centriole Associated Protein 1), a protein implicated in centriole duplication, spindle organization, and chromosome alignment.

What is SPICE1 and Why Is It Important for Cell Division?

Surreal illustration of cell division highlighting SPICE1 and Aurora kinases.

SPICE1 is a protein associated with the centrioles and spindle, essential structures for organizing the microtubule network that separates chromosomes during mitosis. Proper regulation of SPICE1 is critical for maintaining the correct number of centrioles, ensuring proper spindle architecture, and aligning chromosomes accurately. Disruptions in SPICE1 function can lead to severe consequences, including abnormal centriole numbers, multipolar spindles, and misaligned chromosomes.

Researchers have demonstrated that SPICE1 localization and function are regulated by Aurora kinases. In the absence of Aurora kinase activity, SPICE1 remains localized at the centrioles but fails to target the spindle, indicating that phosphorylation by Aurora kinases is necessary for its proper spindle localization. Similarly, a non-phosphorylatable mutant of SPICE1 loses its ability to localize to the spindle, further emphasizing the role of phosphorylation in SPICE1 function.

Centriole Duplication: Ensuring each daughter cell receives the correct number of centrioles.
Spindle Organization: Establishing a bipolar spindle to accurately segregate chromosomes.
Chromosome Alignment: Facilitating proper attachment of chromosomes to microtubules.

Misregulation of SPICE1 phosphorylation can lead to abnormal centriole numbers, spindle multipolarity, and chromosome alignment defects. This suggests that the temporal and spatial control of SPICE1 by Aurora kinases is crucial for correct chromosome segregation. These findings highlight the importance of SPICE1 as a key target of Aurora kinases in maintaining genomic stability.

The Future of Mitotic Research: Leveraging Computational Tools

This research underscores the power of computational approaches in identifying critical mitotic substrates. By combining bioinformatics with experimental validation, researchers can rapidly identify and characterize new targets of Aurora kinases and other mitotic regulators. The development of database-search tools that enable rapid identification of Aurora kinase substrates will accelerate the pace of discovery in this field, leading to a deeper understanding of cell division and its implications for human health. Further studies are necessary to dissect the mechanism of SPICE1 in centriole and spindle function.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1091/mbc.e18-08-0495, Alternate LINK

Title: A Rapid Computational Approach Identifies Spice1 As An Aurora Kinase Substrate

Subject: Cell Biology

Journal: Molecular Biology of the Cell

Publisher: American Society for Cell Biology (ASCB)

Authors: Jovana Deretic, Alastair Kerr, Julie P. I. Welburn

Published: 2019-02-01

Everything You Need To Know

What is the primary role of SPICE1 in cell division?

SPICE1 plays a crucial role in cell division, specifically in centriole duplication, spindle organization, and chromosome alignment. These functions are essential for ensuring that each daughter cell receives the correct number of centrioles, establishing a bipolar spindle for accurate chromosome segregation, and facilitating the proper attachment of chromosomes to microtubules. Errors in SPICE1 function can lead to severe chromosomal abnormalities and genomic instability, highlighting its importance in the process of mitosis.

How do Aurora kinases regulate SPICE1 and what is the impact of this regulation?

Aurora kinases regulate SPICE1 through phosphorylation. The research indicates that SPICE1's localization and function are dependent on Aurora kinase activity. In the absence of Aurora kinase activity, SPICE1 fails to properly localize to the spindle. The phosphorylation by Aurora kinases is necessary for SPICE1's proper function. This regulation is crucial because misregulation of SPICE1 phosphorylation can lead to abnormal centriole numbers, spindle multipolarity, and chromosome alignment defects, which in turn, can cause genomic instability and are associated with diseases like cancer.

Why is accurate chromosome segregation so critical, and what happens when it goes wrong?

Accurate chromosome segregation is fundamental for life because it ensures that each daughter cell receives the correct complement of genetic material. This process is meticulously orchestrated during mitosis by proteins and enzymes, including Aurora kinases and SPICE1. When chromosome segregation goes wrong, it leads to chromosomal instability, a hallmark of cancer and other developmental disorders. Errors can result in cells with an incorrect number of chromosomes (aneuploidy), causing cellular dysfunction and potentially leading to uncontrolled cell growth and disease.

How has computational biology advanced the understanding of mitotic regulation, specifically in relation to SPICE1 and Aurora kinases?

Computational biology has significantly accelerated the identification and understanding of key mitotic regulators like SPICE1 and Aurora kinases. By employing computational approaches that combine phosphorylation site clustering, protein localization data, protein structure analysis, and species conservation data, researchers can rapidly identify new substrates of Aurora kinases. This approach has allowed for the discovery of SPICE1 and the subsequent elucidation of its role in centriole duplication, spindle organization, and chromosome alignment. These computational tools facilitate rapid identification and characterization of mitotic regulators, providing deeper insights into cell division and its implications for human health.

What are the potential implications of research on SPICE1 and Aurora kinases for future medical advancements?

Research on SPICE1 and Aurora kinases holds significant potential for future medical advancements, particularly in the treatment of cancer and other diseases linked to genomic instability. Understanding the mechanisms by which these proteins regulate cell division can lead to the development of targeted therapies that specifically disrupt the abnormal cell division characteristic of cancer cells. The identification of novel Aurora kinase substrates, facilitated by computational approaches, opens up new avenues for drug discovery. By targeting key mitotic regulators, scientists aim to develop more effective and less toxic cancer treatments, ultimately improving patient outcomes.