Mediates nucleation of actin filaments and thereby promotes actin polymerization ( , ). Plays a role in the regulation of actin filament length (By similarity). Required for normal sarcomere organization in the heart, and for normal heart function .
Subcellular locations: Cytoplasm, Myofibril, Sarcomere, Cytoplasm, Myofibril, Cytoplasm, Myofibril, Sarcomere, M line, Cytoplasm, Cytoskeleton
Colocalizes with actin filaments in sarcomeres. Detected close to the M line.
Specifically expressed in heart and skeletal muscles, with higher levels in heart (at protein level). Not expressed in other tissues.