Use of antipeptide antibodies to probe the catalytic activity of p37^v-mos

Several site-directed antipeptide antibodies were generated to probe the kinase function of p37^v-mos. Anti-mos(3755) antibodies allowed autophosphorylation of p37^v-mos, as well as transphosphorylation of exogenously added purified bovine vimentin. Rabbit antipeptide antibodies against v-mos residues 158-170, 194-206, 260-271, and 363-374 and a mouse monoclonal antibody against residues 344-359 completely inhibited p37^v-mos protein kinase activity in vitro. p37^v-mos autophosphorylation and vimentin transphosphorylation were affected similarly. These results suggest important roles for insert and the carboxy-terminal domains in the catalytic activity of p37^v-mos.