Spire type actin nucleation factor 1 (SPIRE1)

Spire type actin nucleation factor 1 (SPIRE1) is a highly conserved actin-regulating protein characterized by multiple functional domains including an N-terminal KIND domain (binding formin proteins), four central WH2 domains (actin binding and nucleation), a globular tail domain-binding motif (links to myosin V), and a C-terminal zinc finger-like FYVE domain (membrane association). SPIRE1 nucleates actin filaments and plays a key role in cytoskeletal organization, intracellular vesicle transport, asymmetric cell division (notably in female germ cell meiosis), and the assembly of nuclear actin filaments during DNA damage repair. Beyond its cytoskeletal functions, SPIRE1 acts as a restriction factor in antiviral immunity by promoting IRF3-dependent signaling downstream of viral RNA sensing, thereby constraining the replication and spread of various viruses. While potentially relevant in the context of infectious disease, SPIRE1 is not currently considered a direct therapeutic target, and no approved drugs are known to interact with it.

Other names

Protein spire homolog 1KIAA1135SPIR1Spir-1spire actin nucleation factor 1spire family actin nucleation factor 1spire homolog 1