Fig. 4. Ice2p fractionates with the ER and not the plasma membrane. Cells were grown in YPD at 30°C to early log phase. (A) Ice2p-Myc (black dashed line) fractionates with the ER but not the Golgi peak of Sec22p (grey solid line) on a sucrose velocity gradient. (B) Ice2p-Myc (black dashed line) fractionates with the ER marker Sec61p (black solid line), but does not fractionate with the plasma-membrane marker Pma1p (grey solid line) on a sucrose density gradient containing EDTA.