Cytoplasmic FMR1-interacting protein 1 (CYFIP1)

Cytoplasmic FMR1-interacting protein 1 (CYFIP1) is an adaptor protein that serves as an integral component of the WAVE regulatory complex (WRC), which couples actin cytoskeletal remodeling to local protein synthesis in neurons. CYFIP1 interacts with Rac1 (a small GTPase), translation initiation factor eIF4E, and the synaptic protein FMR1, thereby repressing translation initiation under basal conditions and promoting the assembly of actin filaments for synaptic plasticity. Synaptic activity releases translational repression by dissociation of the CYFIP1–eIF4E complex, enabling localized mRNA translation needed for plasticity. CYFIP1 also modulates mTOR signaling and plays a key role in brain and neural circuit development, as well as in cancer invasion suppression. Deletion or reduced expression of CYFIP1 is associated with increased susceptibility to neuropsychiatric disorders such as schizophrenia, autism spectrum disorders, epilepsy, and intellectual disability, and its reduced levels are observed in multiple human cancers.

Other names

CYFIP1Cytoplasmic FMR1-interacting protein 1KIAA0068Sra-1 / SRA-1 / SRA1P140SRA-1SHYCSpecifically Rac1-associated protein 1Selective hybridizing cloneCytoplasmic FMRP interacting protein 1

Not applicable—no drugs target CYFIP1 directly. Mechanistically, potential therapies might aim to modulate protein-protein interactions (e.g., with FMR1, Rac1, EIF4E) or restore WAVE complex function, but such approaches remain preclinical.