Protects actin filaments from depolymerization (PubMed:15454575). Required for correct cardiac intercalated disk ultrastructure via maintenance of cell-cell adhesion stability, and as a result maintains cardiac organ morphology, conductance and heart beat rhythm (By similarity). Required for development of normal skeletal muscle morphology and muscle fiber type composition (By similarity). Plays a role in regulating muscle satellite cell activation and survival, as a result promotes muscle fiber recovery from injury and fatigue (By similarity). {ECO:0000250|UniProtKB:O70373, ECO:0000269|PubMed:15454575}. This is the function of XIRP1 (xin actin binding repeat containing 1, ENSG00000168334).