Lipid phosphorylation in isolated rat liver nuclei. Synthesis of polyphosphoinositides at subnuclear level.
Isolated rat liver nuclei and subnuclear fractions synthesize polyphosphoinositides in vitro in a mode dependent on the presence of nuclear membrane, detergent and exogenous substrates. The nuclear membrane is not essential as a source of lipid kinases, since the addition of exogenous phosphatidylinositol or phosphatidylinositol monophosphate to reaction mixtures lacking membranes restores the synthesis of phosphatidylinositol mono- and bisphosphate, respectively. Inositide phosphorylation is best accomplished by high-salt extracted nuclei and pre-detergent lamina. These data suggest that the nucleus, and especially the nuclear periphery, is a cell compartment in which polyphosphoinositide synthesis occurs; this might be related to the progression of phosphatidylinositol metabolism-dependent signals to the genetic apparatus.
Capitani
S
S
Istituto di Anatomia Umana Normale, Università di Ferrara, Italy.
Bertagnolo
V
V
Mazzoni
M
M
Santi
P
P
Previati
M
M
Antonucci
A
A
Manzoli
F A
FA
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000378:metabolism*; D005434:Flow Cytometry; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism* / Q000648:ultrastructure; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols / Q000096:biosynthesis*; D010766:Phosphorylation; D051381:Rats
D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; D000255:Adenosine Triphosphate