Gelsolin

Gelsolin

Illustration of the villin domain, a structural component of gelsolin.

Gelsolin is a multifunctional actin-binding protein that plays a crucial role in the regulation of the actin cytoskeleton. It is involved in various cellular processes, including cell motility, apoptosis, and signal transduction. Gelsolin is known for its ability to sever and cap actin filaments, thereby modulating the dynamics of the actin network within cells.

Structure

Gelsolin is composed of six homologous domains, known as gelsolin domains, which are responsible for its actin-binding and severing activities. The protein undergoes conformational changes upon binding to calcium ions, which activate its actin-severing function. The structure of gelsolin allows it to interact with actin filaments and modulate their length and organization.

Function

Gelsolin's primary function is to regulate the assembly and disassembly of actin filaments. It achieves this by severing actin filaments and capping the newly formed barbed ends, preventing further polymerization. This activity is essential for various cellular processes, such as:

• Cell motility: By remodeling the actin cytoskeleton, gelsolin facilitates cell movement and migration.
• Apoptosis: Gelsolin is involved in the execution phase of apoptosis, where it contributes to the dismantling of the cytoskeleton.
• Signal transduction: Gelsolin participates in signaling pathways by interacting with other proteins and modulating actin dynamics.

Clinical Significance

Mutations in the gelsolin gene can lead to a rare genetic disorder known as familial amyloidosis, Finnish type (FAF), also called AGel amyloidosis. This condition is characterized by the accumulation of amyloid fibrils derived from mutated gelsolin, leading to various symptoms, including cranial neuropathy and corneal lattice dystrophy.

Related Proteins

Gelsolin is part of a family of actin-binding proteins that includes villin, severin, and capG. These proteins share structural similarities and functional roles in actin filament regulation.

Related Pages

• Actin
• Cytoskeleton
• Apoptosis
• Signal transduction