Kinesin-like protein KIF11

Kinesin-like Protein KIF11

Kinesin-like protein KIF11 in action

Kinesin-like protein KIF11, also known as Eg5, is a motor protein that plays a crucial role in the process of mitosis, specifically during the spindle formation and chromosome segregation. KIF11 is a member of the kinesin superfamily, which are proteins known for their ability to convert chemical energy into mechanical work, facilitating intracellular transport along microtubules.

Structure

KIF11 is a homotetrameric protein, meaning it is composed of four identical subunits. Each subunit contains a motor domain at the N-terminus, which is responsible for binding to microtubules and hydrolyzing ATP to generate movement. The central stalk region allows for dimerization, and the C-terminal tail is involved in cargo binding and regulation of motor activity.

Function

KIF11 is essential for the proper assembly of the bipolar spindle during mitosis. It crosslinks and slides antiparallel microtubules apart, which is critical for the separation of spindle poles. This activity ensures that chromosomes are accurately segregated to the daughter cells. KIF11's motor activity is regulated by its interaction with other proteins and by phosphorylation events that occur during the cell cycle.

Mechanism of Action

KIF11 moves along microtubules in a processive manner, meaning it can take multiple steps without detaching. This movement is driven by the hydrolysis of ATP, which induces conformational changes in the motor domains, allowing the protein to "walk" along the microtubule. The coordinated action of KIF11 and other motor proteins ensures the dynamic rearrangement of the microtubule network during cell division.

Clinical Significance

KIF11 is a target for cancer therapy due to its essential role in cell division. Inhibitors of KIF11, such as monastrol, have been developed to disrupt spindle formation, thereby preventing the proliferation of cancer cells. These inhibitors are being studied for their potential use in chemotherapy.

Related Proteins

KIF11 is part of the kinesin-5 family, which includes other motor proteins involved in spindle dynamics. These proteins share structural similarities and functional roles in mitosis.

Related Pages

• Kinesin
• Microtubule
• Mitosis
• Spindle apparatus
• Cell cycle