first calponin homology (CH) domain found in the alpha-actinin family
The alpha-actinin (ACTN) family includes alpha-actinin-1, -2, -3, and -4. They are F-actin cross-linking proteins which are thought to anchor actin to a variety of intracellular structures. ACTN1 mutations cause congenital macrothrombocytopenia. ACTN2 mutations are associated with cardiomyopathies, as well as skeletal muscle disorder. ACTN3 is critical in anchoring the myofibrillar actin filaments and plays a key role in muscle contraction. ACTN4 is associated with cell motility and cancer invasion. It is probably involved in vesicular trafficking via its association with the CART complex, which is necessary for efficient transferrin receptor recycling but not for epidermal growth factor receptor (EGFR) degradation. Members of this family contain two copies of the CH domain. This model corresponds to the first CH domain. CH domains are actin filament (F-actin) binding motifs.