FIG. 5.

Coimmunoprecipitation assay of PP1 phosphatase activity from D. melanogaster extracts. Fifteen micrograms of D. melanogaster embryo or adult extract was immunoprecipitated with either anti-Bif IgG or control (preimmune) IgG coupled to protein G-Sepharose. After washing to remove unbound proteins, phosphatase activity associated with the beads was determined in a phosphatase assay using phosphorylase a as the substrate and including 10 μM SP294 or 100 nM I-2 where indicated. Con, control. +, presence of substance. −, absence of substance.