Enzyme analysis and subcellular fractionation of human peripheral blood lymphocytes with special reference to the localization of putative plasma membrane enzymes

1983 ◽  
Vol 1 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Tarulata Shah ◽  
A. D. B. Webster ◽  
Timothy J. Peters
2001 ◽  
Vol 117 (1-2) ◽  
pp. 133-142 ◽  
Author(s):  
Francesco Amenta ◽  
Elena Bronzetti ◽  
Franco Cantalamessa ◽  
Dahuk El-Assouad ◽  
Laura Felici ◽  
...  

1979 ◽  
Vol 182 (2) ◽  
pp. 537-546 ◽  
Author(s):  
David D. Chaplin ◽  
H. James Wedner ◽  
Charles W. Parker

Phosphorylation of endogenous proteins in subcellular fractions of human peripheral-blood lymphocytes was studied by one- and two-dimensional polyacrylamide-gel electrophoresis. Studies using extensively purified subcellular fractions indicated that the endogenous phosphorylating activity in the particulate fractions was derived primarily from the plasma membrane. Electrophoresis of 32P-labelled subcellular fractions in two dimensions [O'Farrell (1975) J. Biol. Chem.250, 4007–4021] provided much greater resolution of the endogenous phosphoproteins than electrophoresis in one dimension, facilitating their excision from gels for quantification of 32P content. More than 100 cytoplasmic and 20 plasma-membrane phosphorylated species were observed. Phosphorylation of more than 10 cytoplasmic proteins was absolutely dependent on cyclic AMP. In the plasma membrane, cyclic AMP-dependent phosphoproteins were observed with mol.wts. of 42000, 42000, 80000 and 90000 and pI values of 6.1, 6.3, 6.25 and 6.5 respectively. Phosphorylation of endogenous cytoplasmic and plasma-membrane proteins was rapid with t½=5–12s at 25°C. Between 40 and 70% of the 32P was recovered as phosphoserine and phosphothreonine when acid hydrolysates of isolated plasma-membrane phosphoproteins were analysed by high-voltage paper electrophoresis. The presence of cyclic AMP-dependent protein kinase and endogenous phosphate-acceptor proteins in the plasma membranes of lymphocytes provides a mechanism by which these cells might respond to plasma-membrane pools of cyclic AMP generated in response to stimulation by mitogens or physiological modulators of lymphocyte function.


Cytometry ◽  
2003 ◽  
Vol 53A (2) ◽  
pp. 67-78 ◽  
Author(s):  
Suk W. Park ◽  
Noureddine Lomri ◽  
Luiz A. Simeoni ◽  
John P. Fruehauf ◽  
Eugene Mechetner

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