Identification of a 64-kDa protein phosphorylated with glucose in human polymorphonuclear leukocytes in a cell-free system.
We previously reported that a 64-kDa protein (p64) in human polymorphonuclear leukocytes (PMN) was phosphorylated with [gamma-32P]ATP under a micromolar concentration of glucose in a cell-free system. The present paper presents the results of analysis of phosphorylation reaction and the identification of phosphoprotein. The findings that p64 was also phosphorylated with glucose-6-[32P]phosphate and that phosphorylation was inhibited with mannoheptulose suggested that the reaction was mediated by hexokinase. In fact, it was found that [32P]phosphate in glucose-6-[32P]phosphate was incorporated into either p64 or rabbit muscle phosphoglucomutase and that glucose-6-phosphate formation from glucose and ATP was detected in over 100-kDa fraction of PMN cytosol. These results showed that p64 was phosphoglucomutase in PMN and that phosphate incorporation into p64 was a conversion of a phosphate group in glucose-6-phosphate produced by hexokinase. It was further demonstrated by analysis of two-dimensional electrophoresis that p64 phosphorylated with glucose induction was different from another 64-kDa protein phosphorylated by stimulation with formyl-methionyl-leucyl-phenylalanine in vivo.
Shibata
M
M
Department of Antibiotics, National Institute of Health, Tokyo, Japan.
Ohoka
T
T
Mizuno
S
S
Suzuki
K
K
D002474:Cell-Free System; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008970:Molecular Weight; D009504:Neutrophils / Q000737:chemistry / Q000378:metabolism*; D010733:Phosphoglucomutase / Q000032:analysis / Q000378:metabolism*; D010766:Phosphorylation
D010733:Phosphoglucomutase; D005947:Glucose