A differential location of phosphoinositide kinases, diacylglycerol kinase, and phospholipase C in the nuclear matrix.
Several enzymes involved in the phosphoinositide metabolism have been shown to be present in nuclei of rat liver and Friend cells. In this paper we demonstrate that nuclear matrices of mouse NIH 3T3-fibroblasts and rat liver cells, isolated by nuclease treatment and high salt extraction, contain phosphatidylinositol 4-kinase (PdtIns 4-kinase), phosphatidylinositol 4-phosphate 5-kinase (PtdIns(4)P 5-kinase), diacylglycerol kinase, and phospholipase C. By a selective extraction the nucleus can be dissected in the peripheral matrix (lamina-pore complex) and the internal matrix as shown by using marker antibodies. Surprisingly, PtdIns 4-kinase was found exclusively in the peripheral nuclear matrix, whereas PtdIns(4)P 5-kinase was found to be associated to internal matrix structures. Diacylglycerol kinase and phospholipase C activities were also preferentially detected in the internal matrix. These data demonstrate a differential localization of the phosphoinositide kinases in the nucleus and suggest that the phosphoinositide metabolism may play a specific role in the nucleus.
Payrastre
B
B
Department of Molecular Cell Biology, University of Utrecht, The Netherlands.
Nievers
M
M
Boonstra
J
J
Breton
M
M
Verkleij
A J
AJ
Van Bergen en Henegouwen
P M
PM
D019870:1-Phosphatidylinositol 4-Kinase; D016475:3T3 Cells; D000818:Animals; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000201:enzymology*; D003598:Cytoskeletal Proteins / Q000302:isolation & purification; D019852:Diacylglycerol Kinase; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D051379:Mice; D015530:Nuclear Matrix / Q000201:enzymology; D009687:Nuclear Proteins / Q000302:isolation & purification; D010770:Phosphotransferases / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor); D051381:Rats; D011919:Rats, Inbred Strains; D010738:Type C Phospholipases / Q000378:metabolism*
D003598:Cytoskeletal Proteins; D009687:Nuclear Proteins; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); D019852:Diacylglycerol Kinase; D019870:1-Phosphatidylinositol 4-Kinase; C020077:1-phosphatidylinositol-4-phosphate 5-kinase; D010738:Type C Phospholipases