myo-[3H]-inositol loaded erythrocytes and white ghosts: two models to investigate the phosphatidylinositol synthesis in human red cells.
Human erythrocytes were loaded with myo-[(3)H]-inositol in the presence or absence of cytidine trisphosphate to investigate the synthesis of membrane phosphoinositides in the intact red cell. The addition of cytidylic nucleotides to the loading mixture yielded a four-fold increase in the [(3)H]-labeling of the membranes. The [(3)H]-labeling of phosphatidylinositol, phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate was distinguished by two chromatographic techniques. Experiments performed on white ghosts demonstrated the presence of CDP-diacylglycerol synthase and phosphatidylinositol synthase. These results and those already reported allow to discuss a possible turnover of the inositol polar head.
Piatti
E
E
Istituto di Chimica Biologica 'Giorgio Fornaini', Università degli Studi di Urbino, Via Saffi, 2, 61029 Urbino, Italy.
Piacentini
M P
MP
Fraternale
D
D
Bucchini
A
A
Mangani
F
F
Accorsi
A
A
D000328:Adult; D051607:CDP-Diacylglycerol-Inositol 3-Phosphatidyltransferase; D003570:Cytidine Triphosphate / Q000097:blood; D002798:Diacylglycerol Cholinephosphotransferase / Q000097:blood; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007294:Inositol / Q000097:blood*; D008565:Membrane Proteins; D008954:Models, Biological; D010716:Phosphatidylinositols / Q000097:blood*; D017855:Transferases (Other Substituted Phosphate Groups) / Q000097:blood
D008565:Membrane Proteins; D010716:Phosphatidylinositols; D007294:Inositol; D003570:Cytidine Triphosphate; D017855:Transferases (Other Substituted Phosphate Groups); C496766:CDIPT protein, human; D051607:CDP-Diacylglycerol-Inositol 3-Phosphatidyltransferase; D002798:Diacylglycerol Cholinephosphotransferase