CAPZA1

CAPZA1, also known as **capping actin protein of muscle Z-line alpha 1**, is a protein encoded in humans by the *CAPZA1* gene located on chromosome 14q24.3. It belongs to the capping actin protein family, which plays a critical role in regulating actin filament dynamics, particularly in muscle and non-muscle cells.

The CAPZA1 protein functions primarily as a heterodimer with CAPZB, binding to the barbed (plus) ends of actin filaments to stabilize them and prevent further polymerization. This activity is essential for maintaining the structural integrity of actin-based structures, such as the Z-lines in skeletal and cardiac muscle fibers. By capping actin filaments, CAPZA1 helps control cell shape, motility, and mechanical strength, particularly in tissues requiring high contractility.

Mutations in the *CAPZA1* gene have been linked to certain myopathies, including congenital myopathies characterized by muscle weakness and structural abnormalities. These conditions often manifest in early childhood and may involve respiratory or cardiac complications. Research into CAPZA1’s role in disease has focused on its impact on muscle fiber organization and potential therapeutic targets for neuromuscular disorders.

Beyond muscle tissue, CAPZA1 is expressed in various cell types, where it contributes to cytoskeletal organization and signaling pathways. Its expression levels and activity are tightly regulated, reflecting its importance in both developmental and pathological processes. Further study of CAPZA1 may provide insights into actin-based mechanisms in diseases beyond muscle disorders, including cancer and neurodegenerative conditions.