Open AccessEvidence for the Participation of Cytosolic Protein Kinases in Membrane Phosphorylation in Intact Erythrocytes
Author(s) -
PLUT David A.,
HOSEY M. Marlene,
TAO Mariano
Publication year - 1978
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1978.tb12027.x
Subject(s) - phosphorylation , autophosphorylation , protein phosphorylation , cytosol , kinase , protein kinase a , biochemistry , microbiology and biotechnology , membrane protein , biology , membrane , band 3 , chemistry , enzyme
The effects of adenosine 3′:5′‐monophosphate (cyclic AMP) on the phosphorylation of membrane proteins in intact rabbit and human erythrocytes were investigated. The addition of cyclic AMP to intact human or rabbit erythrocytes results in an increase in the incorporation of ortho[ 32 P]phosphate into several membrane protein components which are known to serve as substrates for the cyclic‐AMP‐dependent protein kinases. Thus this increase in protein phosphorylation is probably due to the activation of either soluble or membrane‐bound cyclic‐AMP‐dependent protein kinases. Incubation of human erythrocytes in the presence of ortho[ 32 P]phosphate and cyclic AMP also leads to the phosphorylation of a membrane protein component, band 7, which has not been previously detected in the autophosphorylation of isolated ghosts. Since rabbit erythrocyte membranes do not contain any cyclic‐AMP‐dependent protein kinase, the results suggest that cytoplasmic kinases also play a role in the phosphorylation of membrane proteins in intact cells.