Hyperphosphorylation and SHP-1 association of p32/p30 in motheaten macrophages. (A) Total cell lysates were prepared from D/V or D/C cells and from the spleen cells of normal (+/+) or viable motheaten mice (mev/mev). The lysates were analyzed by SDS-PAGE/Western blotting with antibodies as indicated. (B) Cell lysates from the spleen cells of normal (+/+) or viable motheaten mice (mev/mev) were incubated with an anti–SHP-1 antibody for immunoprecipitation assays or with the synthetic SHP-1-C peptide in binding assays. SHP-1 immunocomplexes (lanes 1 and 2) and SHP-1-C peptide-binding proteins (lanes 3 and 4) were analyzed by SDS-PAGE/Western blotting with antibodies as indicated. (C) Bone marrow-derived macrophages from normal (+/+) or viable motheaten mice (mev/mev) were deprived of growth factors and then stimulated with GM-CSF for various times. Lysates from these cells were analyzed by SDS-PAGE/Western blotting with antibodies as indicated. Positions of phosphotyrosine proteins and protein size markers are indicated.