Filamentous proteins are long, thread-like structures that play crucial roles in the cellular framework of organisms. They are primarily involved in providing structural support, maintaining cell shape, and facilitating movement. Examples of filamentous proteins include actin and tubulin, which are essential components of the cytoskeleton in eukaryotic cells. These proteins can form various types of filaments, such as microfilaments and microtubules, which are vital for processes like cell division and intracellular transport. Their ability to assemble and disassemble dynamically allows cells to adapt to changing conditions and perform essential functions efficiently.