Centromere protein E

Centromere protein E (CENP-E) is a crucial component of the kinetochore, a complex protein structure on chromosomes where the spindle fibers attach during cell division. CENP-E is a motor protein that plays a significant role in chromosome alignment and segregation during mitosis and meiosis.

Structure and Function

CENP-E is a large protein that belongs to the kinesin superfamily of motor proteins. It is characterized by its ability to "walk" along microtubules, which are part of the cell's cytoskeleton. The protein is composed of several domains, including a motor domain that binds to microtubules and a tail domain that interacts with other kinetochore proteins.

During mitosis, CENP-E is essential for the proper attachment of chromosomes to the spindle microtubules. It helps in the congression of chromosomes to the metaphase plate, ensuring that they are correctly aligned before segregation. This alignment is critical for accurate chromosome segregation and the prevention of aneuploidy, a condition where cells have an abnormal number of chromosomes.

Role in Cell Cycle

CENP-E is tightly regulated throughout the cell cycle. It is synthesized during the S phase and becomes active during mitosis. The protein is degraded after mitosis, ensuring that its activity is restricted to the appropriate phase of the cell cycle.

The activity of CENP-E is also regulated by phosphorylation, a process that modifies the protein and affects its function. This regulation is crucial for the timing and fidelity of chromosome segregation.

Clinical Significance

Mutations or dysregulation of CENP-E can lead to chromosomal instability, which is a hallmark of many cancers. As such, CENP-E is a potential target for cancer therapies. Inhibitors of CENP-E are being investigated for their ability to selectively kill cancer cells by disrupting mitosis.

Research and Discoveries

Recent studies have focused on the detailed mechanisms by which CENP-E interacts with microtubules and other kinetochore proteins. Advanced imaging techniques have allowed researchers to visualize CENP-E in action, providing insights into its role in chromosome movement and stability.

Also see

• Kinetochore
• Mitosis
• Microtubule
• Kinesin
• Chromosome segregation