Histidine decarboxylase in human basophilic leukemia (KU-812-F) cells. Characterization and induction by phorbol myristate acetate.
The human leukemic cell line KU-812-F is known to differentiate into mature basophil-like cells under serum-free culture conditions. In the present study, the activity of histidine decarboxylase (HDC), a histamine-forming enzyme, in KU-812-F cells was found to be high, ranging from 10 to 57 pmol/min/mg protein. The great variation in HDC activity appeared to be due to different percentages and degrees of maturity of basophil-like cells during differentiation of this cell line. The enzyme was inhibited by alpha-fluoromethylhistidine but not by carbidopa, was unable to form dopamine from L-3,4-dihydroxyphenylalanine, and had a Km value for histidine of 0.27 mM, indicating that it was HDC and not aromatic amino acid decarboxylase. The HDC activity increased 1.8-fold when the cells were stimulated by phorbol myristate acetate, which is known to activate protein kinase C, and this increase was blocked by staurosporine, a potent inhibitor of protein kinase C.
Mamune-Sato
R
R
First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
Tanno
Y
Y
Maeyama
K
K
Miura
Y
Y
Takishima
T
T
Kishi
K
K
Fukuda
T
T
Watanabe
T
T
D000470:Alkaloids / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002262:Carboxy-Lyases / Q000378:metabolism*; D003513:Cycloheximide / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D006640:Histidine Decarboxylase / Q000378:metabolism*; D006801:Humans; D015471:Leukemia, Basophilic, Acute / Q000201:enzymology* / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects
D000470:Alkaloids; D000001:Calcimycin; D003513:Cycloheximide; D011493:Protein Kinase C; D002262:Carboxy-Lyases; D006640:Histidine Decarboxylase; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate