Figure 3.

K8^−/− sera recognize mitochondrial autoantigens. A) NIH-3T3 cells were double-stained with K8^−/− serum (a, b, d, e; green) that tested positive for autoantigen-binding by immunoblotting, and the Golgi protein gpp130 (a; red) or the mitochondrial protein SOD-2 (b, c, e; red). The merged images of c and d illustrate colocalization of the autoantibody and SOD-2 (e; yellow). B) Mouse liver mitochondrial (lanes 1 and 2), cytosol (lanes 3 and 4), and total liver lysate (lane 5) fractions were blotted with serum from an antibody-positive K8^−/− mouse, with prohibitin (mitochondrial marker) or Hsp70 (cytosolic marker). N, nuclei.