Aktiini

Aktiini is a protein found in muscle and non-muscle cells. In muscle cells, it is a major component of the thin filaments that interact with myosin filaments to cause muscle contraction. Specifically, aktiini is the globular protein that polymerizes to form the filamentous actin (F-actin) structure. This polymerization process is crucial for muscle function, allowing for the sliding of filaments and the generation of force. Each actin monomer, also known as G-actin, binds to ATP and can assemble into a helical polymer.

Beyond muscle, aktiini plays a vital role in the cytoskeleton of all eukaryotic cells. In this context, it is involved in a variety of cellular processes including cell shape maintenance, cell movement (motility), cell division, and intracellular transport. The dynamic assembly and disassembly of aktiini filaments allow cells to change their shape, migrate through tissues, and divide into daughter cells. Various proteins interact with aktiini, regulating its polymerization, depolymerization, and interaction with other cellular components. These interactions are essential for the precise control of aktiini dynamics, which is critical for proper cell function. Defects in aktiini function or regulation can lead to a range of cellular abnormalities and diseases.