Actinfilin (AF)

Actinfilin, a brain-specific Kelch protein, which interacts with F-actin. Actinfilin contains an amino-terminal POZ/BTB domain and carboxyl positioned six tandem Kelch repeats that presumably form six blades of beta-propeller structure of the Kelch domain. Co-immunoprecipitation analyses showed that the amino-terminal POZ domain mediated actinfilin-actinfilin interaction. The recombinant Kelch domain alone was sufficient to mediate binding to F-actin. Immunohistochemistry studies of rat brain sections suggested that actinfilin is broadly expressed in neurons of most regions of the brain. The subcellular localization of actinfilin was studied by biochemical fractionation and immunogold labeling. The results showed the postsynaptic density distribution of actinfilin. Together, these results indicate that actinfilin may be a key player in the actin-based neuronal function.