Alveolitiny

Alveolitiny, known in English as alveolins, are a family of cytoskeletal proteins found in the alveolate supergroup, which includes ciliates, dinoflagellates, and apicomplexan parasites. These proteins localize to the inner membrane complex (IMC), a layer of membranes and associated proteins beneath the plasma membrane that supports the cell cortex in many alveolates. Alveolins are typically rich in coiled-coil domains and assemble into filamentous networks that lie on the cytosolic face of the IMC, forming a structural lattice that helps maintain cell shape and mechanical stability.

Function is closely tied to the cell’s architecture and movement. The alveolin lattice provides a scaffold that supports gliding motility in motile alveolates and stabilizes the pellicle during various cellular processes. In apicomplexan parasites such as Toxoplasma gondii and Plasmodium species, alveolins contribute to host-cell invasion and to daughter cell formation during replication, making them important for parasite biology and viability.

Distribution across alveolates is broad, with different species possessing a range of alveolin proteins that contribute to species-specific pellicle organization and division. Evolutionarily, alveolins are considered a defining feature of the alveolate lineage and have diversified to support distinct life cycles and morphologies.

Research on alveolins uses methods such as gene disruption, protein localization studies, and electron microscopy to understand their assembly and interactions with other cytoskeletal components. Because they are central to parasite structure and invasion, alveolins are of interest for understanding basic cell biology and for potential targets in antiparasitic strategies.