Cytoplasmic FMR1 Interacting Protein 2 (CYFIP2)

CYFIP2 contains 1,252 amino acids and shares 88% sequence identity with CYFIP1. CYFIP1/2 are members of a highly conserved protein family and share approximately 99% sequence identity with their mouse orthologs. CYFIP1 interacts exclusively with FMRP, whereas CYFIP2 also interacts with the FMRP-related proteins FXR1P and FXR2P. The interaction of FMRP and CYFIP involves the domain of FMRP that also mediates homo- and heteromerization, suggesting a competition between interaction among the FXR proteins and interaction with CYFIP.CYFIP1/2 are distributed in an identical pattern in the cytoplasm, showing colocalization with FMRP and ribosomes. Consistent with FMRP and RAC1 localization in dendritic fine structures, CYFIP1/2 are present in synaptosomal extracts.