Fig. 3. Subcellular localization of proMT1-MMP to the slit diaphragm. Immunogold on normal rat kidney using the pro-domain-specific anti-proMT1-MMP IgGs with protein-A/10-nm-gold. ProMT1-MMP antigenic sites are mainly located at the base of the podocyte foot processes (P), along the GBM at points of insertion of the slit diaphragms (arrows). The gold particles revealing the precursor are also found over the ablumenal side of the endothelium (End), facing the GBM (not depicted on this micrograph). Abbreviations: Cap, capillary lumen; GBM, glomerular basement membrane; US, urinary space. Bar, 200 nm.