Actopaxin, also known as alpha-parvin, belongs to the parvin family. It is widely expressed, with highest levels in heart, skeletal muscle, kidney and liver. Actopaxin contains 2 CH (calponin-homology) domains and probably plays a role in the regulation of cell adhesion and cytoskeleton organization. It interacts with integrin-linked protein kinase and probably with actin and the LD1 and LD4 motifs of PXN. Actopaxin binds directly to both F-actin and paxillin LD1 and LD4 motifs. Actopaxin also exhibits robust focal adhesion localization in several cultured cell types but is not found along the length of the associated actin-rich stress fibers. It is absent from actin-rich cell-cell adherens junctions.