Oligomerization of a membrane protein correlates with its retention in the Golgi complex

uncleaved mature VSV G in our experiments. Since the trypsin-cleaved form of VSV G migrated more slowly than T M R (whose tail contains a single amino acid), we deduced that trypsin cleaves the VSV G tall within region A marked on Fig. 8 A. The proteolytic profile generated by trypsin cleavage of Gml differed from that of VSV G. Trypsin treatment of Figure 9 . Trypsin-treated Gml is still oligomerized. Cells expressing VSV G (A) or Gml (B) were metabolically radiolabeled for 5 rain, and then chased for 45 rain. Microsomes were prepared and treated with 20/zg TICK-trypsin for 30 rain at 37°C, then solubilized in MNT and centrifuged on 5-20% sucrose gradients. Fractions were collected, immunoprecipitated using anti-VSV antibody, and analyzed by SDS-PAGE.