FIG. 5.

SMG-2 isoforms of smg smg double mutants. All panels display the SMG-2 region of Western blots reacted with anti-SMG-2 antibody. SMG-2 isoforms which accumulated in smg-5, smg-6, and smg-7 single mutants are shown in row 1. SMG-2 isoforms which accumulated in smg smg double mutants are shown at the intersections of rows and columns. For example, row 2, column 1, is a smg-1 smg-5 double mutant; row 3, column 1, is a smg-3 smg-5 double mutant, etc. Alleles used to construct the double mutants were smg-1(r861), smg-3(r867), smg-4(ma116), smg-5(r860), smg-6(r896), and smg-7(r1131). All strains were grown at 20°C except those containing smg-7(r1131). Because r1131 is temperature sensitive, all strains involving this mutation were grown at 25°C. Experiments not shown demonstrate that growth at 25°C does not influence the relative proportions of SMG-2 and phosphorylated SMG-2 in the wild type or smg-5 and smg-6 single mutants.