Fig. 5. Gcs1p is weakly associated with membrane fraction. The ER/mitochondria-enriched fraction (P13) from wild-type yeast was treated with 1 M NaCl, 0.1 M Na₂CO₃ or buffer (Mock) on ice for 30 minutes, followed by centrifugation at 150,000 g for one hour. The resulting supernatant and pellet fractions were analyzed by western blotting using anti-Gcs1p or anti-porin antibodies.