Nascent VLDL phospholipid composition is altered when phosphatidylcholine biosynthesis is inhibited: evidence for a novel mechanism that regulates VLDL secretion

SEC14p is required for protein transport from the yeast Golgi complex. We describe a quantitative analysis of yeast bulk membrane and Golgi membrane phospholipid composition under conditions where Golgi secretory function has been uncoupled from its usual SEC14p requirement. The data demonstrate that SEC14p specifically functions to maintain a reduced phosphatidylcholine content in Golgi membranes and indicate that overproduction of SEC14p markedly reduces the apparent rate of phosphatidylcholine biosynthesis via the CDP-choline pathway in vivo. We suggest that SEC14p serves as a sensor of Golgi membrane phospholipid composition through which the activity of the CDP-choline pathway in Golgi membranes is regulated such that a phosphatidylcholine content that is compatible with the essential secretory function of these membranes is maintained.

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Phosphatidylcholine biosynthesis in celery cell suspension cultures with altered sterol compositions

Physiologia Plantarum ◽

10.1034/j.1399-3054.1991.830412.x ◽

1991 ◽

Vol 83 (4) ◽

pp. 605-610

Author(s):

Carole E. Rolph ◽

L. John Goad

Keyword(s):

Cell Suspension ◽

Cell Suspension Cultures ◽

Suspension Cultures ◽

Phosphatidylcholine Biosynthesis

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Platelet Functions in Relation to Dietary Fats in Farmers from two Regions of France

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648685 ◽

1978 ◽

Vol 40 (02) ◽

pp. 518-531 ◽

Cited By ~ 24

Author(s):

S Renaud ◽

E Dumont ◽

F Godsey ◽

A Suplisson ◽

C Thevenon

Keyword(s):

Platelet Aggregation ◽

Platelet Rich Plasma ◽

Plasma Cholesterol ◽

Phospholipid Composition ◽

Saturated Fat ◽

Phosphatidyl Inositol ◽

Phosphatidyl Serine ◽

Dietary Fats ◽

Platelet Phospholipid ◽

Platelet Functions

SummaryTo determine whether the long-term feeding of dietary fats affect platelet functions in man, platelet aggregation (to thrombin ADP, collagen, epinephrine) and clotting activity of platelet-rich plasma (PRP), platelet-poor plasma and of washed platelets, were studied in a mobile-laboratory in 44 healthy male farmers (40-45 years) from two French regions Var and Moselle, in relation to lipemia, glycemia, dietary nutriments, and platelet phospholipid composition. In the Moselle subjects, the platelet clotting activity of PRP and of washed platelets, the platelet aggregation to thrombin and ADP, were highly significantly (p <0.001) increased as compared to those of Var, but not the plasma cholesterol, which was identical in the two regions.In Moselle, the intake of total calories, total lipids and saturated fats was higher than in the Var.However, it was only with the saturated fat intake (mostly stearic acid) that the platelet clotting activity (p <0.01) and the platelet aggregation (p <0.001) were highly significantly correlated. The platelet clotting activity was also significantly (p <0.001) correlated with the fatty acid composition of the platelet phospholipid fractions phosphatidyl serine + phosphatidyl inositol.

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