Phosphoinositide signalling in nuclei of Friend cells: DMSO-induced differentiation reduces the association of phosphatidylinositol-transfer protein with the nucleus.
Friend erythroleukemia cells have a nuclear phosphoinositide cycle which is related to both mitogen-stimulated cell growth and erythorid differentiation. Because of the important role of the phosphatidylinositol-transfer protein (PI-TP) in phosphatidylinositol 4,5-bisphosphate (PtdInsP2) synthesis, we have analysed nuclei isolated from Friend cells for the presence of PI-TP. By Western Blotting it was demonstrated that both intact nuclei and nuclei deprived of the outer membrane contained the PI-TP alpha isoform. Upon induction of erythroid differentiation by DMSO, the amount of nuclear PI-TP alpha was greatly diminished. As shown previously, under these same conditions, nuclear phospholipase C beta1 (PLC beta1) is down-regulated as well.
Rubbini
S
S
Institute of Anatomy, University of Bologna, Italy.
Cocco
L
L
Manzoli
L
L
Lutterman
J
J
Billi
A M
AM
Matteucci
A
A
Wirtz
K W
KW
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D019084:Fluorescent Antibody Technique, Indirect; D007527:Isoenzymes / Q000378:metabolism; D004915:Leukemia, Erythroblastic, Acute; D008565:Membrane Proteins; D051379:Mice; D008854:Microscopy, Electron; D010716:Phosphatidylinositols / Q000378:metabolism*; D054799:Phospholipase C beta; D049294:Phospholipid Transfer Proteins; D015398:Signal Transduction; D010738:Type C Phospholipases / Q000378:metabolism
D002352:Carrier Proteins; D007527:Isoenzymes; D008565:Membrane Proteins; D010716:Phosphatidylinositols; D049294:Phospholipid Transfer Proteins; D010738:Type C Phospholipases; D054799:Phospholipase C beta; C518034:Plcb1 protein, mouse; D004121:Dimethyl Sulfoxide