Calcium ion stimulated endogenous protein kinase catalyzed phosphorylation of basic proteins in myelin subfractions and myelin-like membrane fraction from rat brain

Biochemistry ◽  
1980 ◽  
Vol 19 (23) ◽  
pp. 5363-5371 ◽  
Author(s):  
Prakash V. Sulakhe ◽  
Elena H. Petrali ◽  
Evelyn R. Davis ◽  
Brenda J. Thiessen
Keyword(s):  
Protein Kinase ◽  
Rat Brain ◽  
Calcium Ion ◽  
Membrane Fraction ◽  
Basic Proteins ◽  
Endogenous Protein ◽  
Myelin Subfractions

Investigations on myelinogenesis in vitro: I. The occurrence of endogenous protein kinase and its role in the phosphorylation of myelin basic proteins in “Myelin-like membranes” isolated from cerebral cell cultures

1987 ◽  
Vol 7 (2) ◽  
pp. 151-157
Author(s):  
G. Shanker ◽  
R. A. Pieringer
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Membrane Fraction ◽  
Primary Cultures ◽  
Embryonic Mouse ◽  
Basic Proteins ◽  
Endogenous Protein ◽  
Dependent Protein ◽  
Endogenous Proteins

The presence of a protein kinase capable of phosphorylating endogenous as well as exogenously added myelin basic proteins has been demonstrated in a myelin-like membrane fraction isolated from reaggregating and surface adhering, primary cultures of cells dissociated from embryonic mouse brain. Only the large and small components of myelin basic proteins were found to be phosphorylated when myelin-like membrane fraction was incubated with [γ-32P]ATP. The protein kinase endogenous to the myelin-like membrane fraction was mainly of the cyclic AMP independent type. There was very little cyclic AMP dependent or cyclic GMP dependent protein kinase activities in this myelin-like fraction. Although the myelin basic proteins were the only endogenous proteins phosphorylated, protein kinase of the myelin-like membrane was capable of catalyzing the phosphorylation of exogenous substrates, such as histones.

Comparison of an endogenous protein kinase C substrate in rat aorta with rat brain MARCKS

1992 ◽  
Vol 116 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Dayuan Zhao ◽  
Morley D. Hollenberg ◽  
David L. Severson
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Rat Brain ◽  
Rat Aorta ◽  
Kinase C ◽  
Endogenous Protein

scholarly journals UDP-galactose-ceramide galactosyltransferase in rat brain myelin subfractions during development

1980 ◽  
Vol 186 (3) ◽  
pp. 959-969 ◽  
Author(s):  
O Koul ◽  
K H Chou ◽  
F B Jungalwala
Keyword(s):  
Rat Brain ◽  
Membrane Fraction ◽  
Specific Activity ◽  
Gradient Centrifugation ◽  
Proteolipid Protein ◽  
Myelin Proteins ◽  
Sucrose Density Gradient Centrifugation ◽  
Microsomal Membranes ◽  
Myelin Subfractions ◽  
Myelin Fraction

The localization and activity of the enzyme UDP-galactose-hydroxy fatty acid-containing ceramide galactosyltransferase is described in rat brain myelin subfractions during development. Other lipid-synthesizing enzymes, such as cerebroside sulphotransferase, UDP-glucose-ceramide glucosyltransferase and CDP-choline-1,2-diacylglycerol cholinephosphotransferase, were also studied for comparison in myelin subfractions and microsomal membranes. The purified myelin was subfractionated by isopycnic sucrose-density-gradient centrifugation. Four myelin subfractions, three floating respectively on 0.55 M- (light-myelin fraction), 0.75 M- (heavy-myelin fraction) and 0.85 M-sucrose (membrane fraction), and a pellet, were isolated and purified. At all ages, 70-75% of the total myelin proteins was found in the heavy-myelin fraction, whereas 2-5% of the protein was recovered in the light-myelin fraction, and about 7-12% in the membrane fraction. Most of the galactosyltransferase was associated with the heavy-myelin and membrane fractions. Other lipid-synthesizing enzymes studied appeared not to associate with purified myelin or myelin subfractions, but were enriched in the microsomal-membrane fraction. During development, the specific activity of the microsomal galactosyltransferase reached a maximum when the animals were about 20 days old and then declined. By contrast the specific activity of the galactosyltransferase in the heavy-myelin and membrane fractions was 3-4 times higher than that of the microsomal membranes in 16-day-old animals. The specific activity of the enzyme in the heavy-myelin fraction sharply declined with age. Chemical and enzymic analyses of the heavy-myelin and membrane myelin subfractions at various ages showed that the membrane fraction contained more proteins in relation to lipids than the heavy-myelin fraction. The membrane fraction was also enriched in phospholipids compared with cholesterol and contrined equivalent amounts of 2':3'-cyclic nucleotide 3'-phosphohydrolase compared with heavy- and light-myelin fractions. The membrane fraction was deficient in myelin basic protein and proteolipid protein and enriched in high-molecular-weight proteins. The specific localization of galactosyltransferase in heavy-myelin and membrane fractions at an early age when myelination is just beginning suggests that it may have some role in the myelination process.

Effect of Thrombin on Phosphorylation of Platelet Membrane Proteins

1976 ◽  
Vol 35 (03) ◽  
pp. 635-642 ◽  
Author(s):  
M Steiner
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Qualitative Change ◽  
Protein Kinase Activity ◽  
Protein Substrates ◽  
Phosphoprotein Phosphatase ◽  
Progressive Loss ◽  
Platelet Membranes ◽  
Endogenous Protein ◽  
Considerable Loss

SummaryThe effect of thrombin on the phosphorylating activity of platelet membranes was compared to that of trypsin. Preincubation of non-32P phosphorylated platelet membranes with or without either of these two enzymes resulted in a considerable loss of membrane protein kinase activity which was most severe when trypsin was used. Protein kinase activity and endogenous protein acceptors decreased in parallel. 32P-phosphorylated membranes showed a slow but progressive loss of label which was accelerated by trypsin. Thrombin under these conditions prevented the loss of 32P-phosphate. These results are interpreted to indicate a thrombin-induced destruction of a phosphoprotein phosphatase. The protein kinase activity of phosphorylated platelet membranes using endogenous or exogenous protein substrates showed a significant reduction compared to non-phosphorylated membranes suggesting a deactivation of protein kinase by phosphorylation of platelet membranes. Neither thrombin nor trypsin caused a qualitative change in the membrane polypeptides accepting 32P-phosphate but resulted in quantitative alterations of their ability to become phosphorylated.

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