Identification of protein kinase C and its potential substrate in Entamoeba histolytica.
1. Protein kinase C (PKC) activity has been identified in various strains of the human parasite, Entamoeba histolytica. 2. An amoebic protein of mol. wt 78,000 was recognized by polyclonal antibodies raised against the 82,000 mol. wt rat brain protein kinase C. 3. A partially purified PKC preparation from E. histolytica phosphorylated histone I in the presence of calcium, phospholipids and diacylglycerol, and specifically bound tritiated phorbol ester at an apparent KD of 9 nM. 4. A relocalization of the amoebic PKC activity from the cytosol to the membrane fraction was observed when trophozoites were actively phagocytising bacteria. Under these conditions, a labelled phosphoprotein of mol. wt 68,000 was identified. 5. Similar to what was found during macrophage activation, a myristoylated mol. wt 68,000 protein was detected in amoebae grown in the absence of bacteria, but not in amoebae which were active in phagocytosis.
De Meester
F
F
MacAuthur Center for Molecular Biology of Parasitic Diseases, Weizmann Institute of Science, Rehovot, Israel.
Mirelman
D
D
Stolarsky
T
T
Lester
D S
DS
D000818:Animals; D001921:Brain / Q000201:enzymology; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D004075:Diglycerides / Q000494:pharmacology; D004748:Entamoeba histolytica / Q000201:enzymology*; D006657:Histones / Q000378:metabolism; D015151:Immunoblotting; D008970:Molecular Weight; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism; D010587:Phagocytosis; D015240:Phorbol 12,13-Dibutyrate / Q000378:metabolism / Q000494:pharmacology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000737:chemistry / Q000378:metabolism*; D051381:Rats
D004075:Diglycerides; D006657:Histones; D009227:Myristic Acids; D019814:Myristic Acid; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; D002118:Calcium