nucleotide-binding domain (NBD) of actin-related protein 1 (Arp1) and similar proteins
Arp1, also called centractin, actin-like protein, alpha-centractin, actin-RPV, or centrosome-associated actin homolog, may be a component of a multi-subunit centrosomal complex involved in microtubule-based vesicle motility. In yeast, actin-related protein is essential for viability and is associated with the centrosome. In vertebrates, Arp1 is a core component of the dynactin complex which assists cytoplasmic dynein by increasing its processivity and by regulation of its cargo binding. The dynactin complex is required for the spindle translocation late in anaphase and is involved in a cell wall synthesis checkpoint. ARP1 forms the backbone filament of the dynactin rod structure and serves as the scaffold for the remaining subunits. It is required for proper orientation of the mitotic spindle. Arp1 is the only actin-related protein known to form actin-like filaments. Human Arp1/centractin is encoded by the ACTR1A gene.