期刊
JOURNAL OF IMMUNOLOGY
卷 164, 期 2, 页码 1020-1028出版社
AMER ASSOC IMMUNOLOGISTS
DOI: 10.4049/jimmunol.164.2.1020
关键词
-
类别
The interplay between serine/threonine and tyrosine phosphorylation mas studied in human neutrophils, The direct effects of calyculin and okadaic acid, potent inhibitors of PP1 and PP2A serine/threonine phosphatases, on the patterns of neutrophil phosphorylation, and their effects on the responses of neutrophils to CD32 cross-linking were monitored. After a 2-min incubation with 10(-6) M calyculin, a transient tyrosine phosphorylation of a subset of proteins, among which Cbl and Syk, was observed. After a longer incubation (>5 min) with calyculin, concomitant with an accumulation of serine and threonine phosphorylation, neutrophil responses to CD32 cross-linking were selectively altered, Tyrosine phosphorylation of Cbl in response to CD32 crosslinking was inhibited by calyculin, and this inhibition was linked with a slower electrophoretic mobility of Cbl as a consequence of its phosphorylation on serine/threonine residues. However, tyrosine phosphorylation of Syk and of the receptor itself were not affected. Furthermore, the mobilization of intracellular calcium stimulated by CD32 cross-linking was totally abrogated by calyculin. Finally, the stimulation of superoxide production observed in response to CD32 cross-linking was enhanced in calyculin-treated cells. These results suggest that serine/threonine phosphorylation events regulate the signaling pathways activated by CD32 cross-linking in neutrophils and identify a novel mechanism of modulation of the functional responsiveness of human neutrophils to CD32 cross-linking.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据