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Hexadecylphosphocholine inhibits translocation of CTP:choline-phosphate cytidylyltransferase in Madin-Darby canine kidney cells.

Hexadecylphosphocholine inhibits translocation of CTP:choline-phosphate cytidylyltransferase in Madin-Darby canine kidney cells.

Authors :
Geilen CC
Wieder T
Reutter W
Source :
The Journal of biological chemistry [J Biol Chem] 1992 Apr 05; Vol. 267 (10), pp. 6719-24.
Publication Year :
1992

Abstract

The mechanism of the inhibition of phosphatidylcholine biosynthesis by the phospholipid analogue, hexadecylphosphocholine, was investigated in Madin-Darby canine kidney cells. In the presence of 50 mumol/liter hexadecylphosphocholine, there was a translocation of CTP:choline-phosphate cytidylyltransferase (EC 22.7.7.15) activity from the membranes to the cytosol of the cells. Since we recently demonstrated that hexadecylphosphocholine also inhibits protein kinase C in vitro, [methyl-3H]choline labeling experiments were repeated with phorbol ester-desensitized cells. In these cells the same inhibitory effect of hexadecylphosphocholine was measured. As a consequence of inhibition, the [methyl-3H]choline incorporation into the phosphocholine pool was increased time-dependently. In addition, there was no evidence for a difference between the choline uptake of control and hexadecylphosphocholine-treated cells. Likewise, the amount of diacylglycerol, a known activator of the translocation process, was not reduced. Finally, we showed that the inhibitory effect of hexadecylphosphocholine on CTP:choline-phosphate cytidylyltransferase translocation cannot be explained by the detergent properties of this phospholipid analogue. Therefore, we suggest a direct inhibitory effect of hexadecylphosphocholine on the translocation of CTP:choline-phosphate cytidylyltransferase.

Details

Language :
English
ISSN :
0021-9258
Volume :
267
Issue :
10
Database :
MEDLINE
Journal :
The Journal of biological chemistry
Publication Type :
Academic Journal
Accession number :
1313020