Subcellular distribution of ubiquitin–protein conjugates in the hippocampus following transient ischemia

Ubiquitin-protein conjugates in the hippocampus were analyzed by immunoblotting with a monoclonal anti-ubiquitin antibody. In the CA1 region, Triton X-100 insoluble ubiquitin-protein conjugates increased after 24 hr following 20 min of ischemia. When the total hippocampi were fractionated subcellularly, ubiquitin-protein conjugates increased in the particulate, especially in the mitochondrial fraction. The ubiquitin-protein conjugates were solubilized by SDS, or were partially solubilized by urea. The results indicate that insoluble ubiquitin-protein conjugates increase after ischemia.