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Phosphorylation of cytosolic proteins by resting and activated human neutrophils

Journal Article · · Blood; (United States)
OSTI ID:5982164

A study was conducted on the phosphorylation of proteins in the neutrophil cytosol in response to phorbol myristate acetate (PMA) and N-formyl-methionyl-leucyl-phenylalanine (fMLP). Autoradiography of gel electrophoretograms prepared from neutrophils incubated with /sup 32/P in the presence and absence of the activators showed nine proteins whose state of phosphorylation was affected by neutrophil activation. /sup 32/P was gained by eight of these proteins and was lost by the ninth. For all but one of these proteins, the change in the extent of labeling appeared to reach completion by one to two minutes. It was possible to quantitate the changes in /sup 32/P content of three of the nine proteins. One of these was the 20-kD protein that lost label when the neutrophils were activated. Quantitation showed that over half the /sup 32/P present in this protein in the resting state was gone within 0.2 minutes after activation. The other two were proteins weighing 11 and 69 kD. The phosphorylation characteristics of these two proteins differed, depending on whether activation had been carried out with PMA or fMLP. These differences in protein phosphorylation support other evidence suggesting that PMA and fMLP do not activate neutrophils by identical biochemical pathways.

Research Organization:
Tufts-New England Medical Center, Boston, MA
OSTI ID:
5982164
Journal Information:
Blood; (United States), Journal Name: Blood; (United States) Vol. 64:4; ISSN BLOOA
Country of Publication:
United States
Language:
English