Matrix metalloproteinase-9 has recently emerged as an important molecule in control of
extracellular proteolysis in the synaptic plasticity. However, no synaptic targets for its
enzymatic activity had been identified before. In this report, we show that β-dystroglycan
comprises such a neuronal activity-driven target for matrix metalloproteinase-9. This notion
is based on the following observations.(i) Recombinant, autoactivating matrix
metalloproteinase-9 produces limited proteolytic cleavage of β-dystroglycan.(ii) In neuronal …