HISTIDYL PHOSPHORYLATION OF P36 IN RAT HEPATOMA FAO CELLS IN-VITRO AND IN-VIVO

We have previously shown that a membrane-associated P36 from rat liver was in vitro phosphorylated at His residue(s) with a phosphoric amide bond (FEBS Left., 319:75-79, 1993), and the activity was solubilized and partially purified (J. Biol. Chem., 269:9030-9037, 1994). The pres ent study demonstrates that the P36 histidyl phosphorylation occurs in rat hepatoma cells under normal conditions. Phosphorylation and depho sphorylation of histidine as well as those of serine, threonine and ty rosine residues may also play an important role in animal cells. (C) 1 994 Academic Press, Inc.