Cytosolic protein phosphatase may turn off activated NADPH oxidase in guinea pig neutrophils.
Cytosolic protein phosphatase may turn off activated NADPH oxidase in guinea pig neutrophils.
复制标题
胞浆蛋白磷酸酶可能会关闭豚鼠中性粒细胞中活化的 NADPH 氧化酶。
DOI：
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发表时间：
1993
影响因子：
3.9
通讯作者：
S. Ishibashi
中科院分区：
文献类型：
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作者：
M. Yamaguchi;J. Sasaki;M. Kuwana;M. Sakai;N. Okamura;S. Ishibashi
蛋白磷酸酶抑制剂冈田酸和花萼蛋白 A 可增强并延长 N-甲酰基-甲硫氨酰-亮氨酰-苯丙氨酸诱导的豚鼠中性粒细胞中超氧阴离子 (O2-) 的产生。由佛波醇12-肉豆蔻酸酯13-乙酸酯刺激的中性粒细胞制备的膜级分中NADPH氧化酶的活性通过添加来自静息中性粒细胞的胞质溶胶而失活，NADPH氧化酶的这种失活也被蛋白磷酸酶抑制剂抑制。我们之前报道过蛋白激酶 C 对 46 kDa 蛋白的磷酸化是 NADPH 氧化酶依赖性超氧阴离子产生的激活机制之一。在胞质级分中，我们发现蛋白磷酸酶活性可催化 32P 标记的磷蛋白（包括 46 kDa 蛋白）的去磷酸化。添加冈田酸和花萼蛋白 A 可以抑制 46-kDa 蛋白的去磷酸化。这些结果表明，蛋白磷酸酶对 46-kDa 蛋白的去磷酸化参与了 NADPH 氧化酶的失活。豚鼠中性粒细胞中的 NADPH 氧化酶活性可能受到蛋白激酶 C 和蛋白磷酸酶对 46-kDa 蛋白的磷酸化/去磷酸化状态的调节。
Protein phosphatase inhibitors, okadaic acid and calyculin A, potentiated and elongated N-formyl-methionyl-leucyl-phenylalanine-induced superoxide anion (O2-) production in guinea pig neutrophils. The activity of NADPH oxidase in the membrane fraction prepared from phorbol 12-myristate 13-acetate-stimulated neutrophils was inactivated by the addition of the cytosol from resting neutrophils, such inactivation of NADPH oxidase was also suppressed by the protein phosphatase inhibitors. We previously reported that phosphorylation of the 46-kDa protein by protein kinase C is one of the activation mechanisms of NADPH oxidase-dependent superoxide anion production. In the cytosol fraction, we found protein phosphatase activity that catalyzed dephosphorylation of 32P-labeled phosphoproteins including the 46-kDa protein. Dephosphorylation of the 46-kDa protein was inhibited by the addition of okadaic acid and calyculin A. These results indicate that dephosphorylation of the 46-kDa protein by protein phosphatase is involved in the inactivation of NADPH oxidase. NADPH oxidase activity in guinea pig neutrophil may be regulated by the phosphorylation/dephosphorylation state of the 46-kDa protein by protein kinase C and protein phosphatase.