The process that targets activated MT-MMPs to the plasma membrane is unclear but presumed to involve standard golgi transport mechanisms. The cytoplasmic domain of MT1-MMP is critical for the localization to discrete regions of the cell surface (Urena et al. 1999) and involved in internalization which has a regulatory role. The cytoplasmic domain mediates interactions with specific cell-surface proteins such as C1Q binding protein which may serve to direct the MMP from the golgi to the cell surface (Rozanov et al. 2002).