Relationship between uridine kinase activity and rate of incorporation of uridine into acid-soluble pool and into RNA during growth cycle of rat hepatoma cells

1969 ◽  
Vol 73 (3) ◽  
pp. 233-249 ◽  
Author(s):  
Peter G. W. Plagemann ◽  
Gary A. Ward ◽  
Brian W. J. Mahy ◽  
Michal Korbecki
Keyword(s):  
Kinase Activity ◽  
Growth Cycle ◽  
Hepatoma Cells ◽  
Uridine Kinase ◽  
Rat Hepatoma ◽  
Rat Hepatoma Cells

scholarly journals CHOLINE METABOLISM AND MEMBRANE FORMATION IN RAT HEPATOMA CELLS GROWN IN SUSPENSION CULTURE

1969 ◽  
Vol 42 (3) ◽  
pp. 766-782 ◽  
Author(s):  
Peter G. W. Plagemann
Keyword(s):  
Stationary Phase ◽  
Suspension Culture ◽  
Growth Cycle ◽  
Hepatoma Cells ◽  
Cellular Membranes ◽  
Membrane Structures ◽  
Isopycnic Centrifugation ◽  
Fresh Culture ◽  
Rat Hepatoma ◽  
Rat Hepatoma Cells

The incorporation of methyl-labeled choline into phosphorylcholine and phosphatidylcholine of cellular membranes by Novikoff rat hepatoma cells (line N1S1-67) during growth in suspension culture was investigated. Upon initiation of a fresh culture at 105 cells/ml, the rate of synthesis of phosphorylcholine by the cells was four to five times greater than that of the synthesis of phosphatidylcholine. While the rate of synthesis of the latter remained relatively constant, the rate of phosphorylation of choline decreased progressively during the course of the growth cycle of the culture to 10–20% of the initial rate when the culture reached stationary phase at 3 x 106 cells/ml. The decrease in phosphorylcholine synthesis during the growth cycle was not due to depletion of choline in the medium or a decrease in its concentration, but was correlated with a decrease in choline kinase activity of the cells as measured in cell-free extracts. Newly synthesized phosphatidylcholine was detectable in cells only as an integral part of cellular membranes. Its distribution among various cytoplasmic membrane structures separated by isopycnic centrifugation in sucrose density gradients remained relatively constant during the growth cycle. About 50% was associated with the mitochondria, and the remainder with plasma membrane fragments and other membranous structures with mean densities of about 1.15 and 1.13 g/cm3, respectively. However, the density of the mitochondria increased from about 1.167 g/cm3 in early exponential phase cells to about 1.190 g/cm3 in stationary phase cells. The finding that the density of the entire propulation of mitochondria changed simultaneously and progressively is in agreement with the view that mitochondria grow by addition of phospholipids and structural proteins and increase in number by division.

scholarly journals Identification of the insulin receptor tyrosine residues undergoing insulin-stimulated phosphorylation in intact rat hepatoma cells.

1988 ◽  
Vol 263 (1) ◽  
pp. 350-359 ◽  
Author(s):  
H E Tornqvist ◽  
J R Gunsalus ◽  
R A Nemenoff ◽  
A R Frackelton ◽  
M W Pierce ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Hepatoma Cells ◽  
Tyrosine Residues ◽  
Rat Hepatoma ◽  
Rat Hepatoma Cells
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