UCSF

Actin has been extensively studied in the cytoplasm for its structural functions such as cell morphology, movement, and adhesion. On the other hand, research on the functions of actin in the nucleus has only begun to emerge. Previous work in the lab has shown nuclear actin filaments form in response to DNA damage. The development of a nuclear specific actin probe was crucial in visualizing actin filaments in the nucleus and determining that actin assembly is required for the DNA damage response. Actin regulators are involved in controlling when and where actin is assembled and recent research has found that the Actin Related Protein 2/3 (Arp2/3) complex, an actin nucleator that creates branches off existing filaments, is required for efficient DNA repair. Our lab has found that the Arp2/3 complex nucleation activity is not disrupted by DNA binding and shown that the Arp2/3 complex is required for efficient cell proliferation and non-homologous end joining (NHEJ) during immunoglobulin class switch recombination.