Figure 6.

Model of p70^S6k regulation and targeting by neurabin. In nerve cell bodies, neurabin binds cytosolic p70^S6k. Subsequently, neurabin binds F-actin and is targeted to nerve terminals. p70^S6k kinase activity is enhanced by its interaction with neurabin, but its function at the synapse is unknown. Kinase activity may be regulated in response to mitogenic stimuli or possibly neuronal activity. (Inset) Neurabin oligomers bind the C terminus of p70^S6k via a single PDZ domain and bind F-actin with a unique N-terminal actin binding region. Oligomerization is potentially mediated by coiled–coiled structure at the C terminus of neurabin.