Regulation of the antigen-induced F-actin response in rat basophilic leukemia cells by protein kinase C.
Regulation of the antigen-induced F-actin response in rat basophilic leukemia cells by protein kinase C.
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DOI：
10.1083/jcb.112.6.1157
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发表时间：
1991-03
期刊：
影响因子：
--
通讯作者：
Apgar JR
中科院分区：
文献类型：
--
作者：
Apgar JR
多价抗原能够结合并交联大鼠嗜碱性白血病（RBL）细胞上的IgE受体，诱导丝状肌动蛋白含量快速而持续的增加。肌动蛋白的这种重组可能是脱粒过程中细胞形态变化的原因。抗原刺激的肌动蛋白聚合可以通过蛋白激酶抑制剂以剂量依赖性方式阻断，所述蛋白激酶抑制剂也阻断脱粒。相反，刺激蛋白激酶C（PKC）的试剂如PMA、1，2-二辛酰基-sn-甘油（diC 8）和1-油酰基-2-乙酰基-甘油（OAG）也激活F-肌动蛋白的升高，尽管它们本身对脱粒没有影响。可由PKC激活剂刺激的肌动蛋白反应也可被蛋白激酶抑制剂阻断，表明PMA和OAG诱导的反应可能是通过激活蛋白激酶。通过长期（20小时）暴露于PMA的RBL细胞的PKC活性耗尽，也抑制了F-肌动蛋白反应时，细胞被刺激与多价抗原或OAG。外部Ca++，这是一个脱粒的绝对要求，是不必要的上升F-肌动蛋白，但可能会调节的反应。此外，离子霉素，诱导一个大的Ca++流入，不刺激F-肌动蛋白增加，即使在剂量，导致脱粒。这些结果表明，蛋白激酶，如PKC的激活，可能是负责在RBL细胞中的肌动蛋白的聚合的信号和细胞内Ca++的上升是既不必要也不充分的这种反应。
Multivalent antigen that is capable of binding to and crosslinking the IgE receptors on rat basophilic leukemia (RBL) cells, induces a rapid and sustained rise in the content of filamentous actin. This reorganization of the actin may be responsible for changes in cellular morphology during the degranulation process. The antigen-stimulated polymerization of actin can be blocked in a dose-dependent manner by protein kinase inhibitors which also block degranulation. Conversely, reagents such as PMA, 1,2-dioctanoyl-sn-glycerol (diC8), and 1-oleoyl-2- acetyl-glycerol (OAG) which stimulate protein kinase C (PKC) also activate the rise in F-actin, although they have no effect on degranulation by themselves. The actin response which can be stimulated by the PKC activators can also be blocked by protein kinase inhibitors indicating that the PMA- and OAG-induced response is probably through activation of a protein kinase. Depletion of PKC activity through long term (20 h) exposure of RBL cells to PMA, also inhibited the F-actin response when the cells were stimulated with either multivalent antigen or OAG. External Ca++, which is an absolute requirement for degranulation, is not necessary for the rise in F-actin, but may modulate the response. Furthermore, ionomycin, which induces a large Ca++ influx, does not stimulate the F-actin increase even at doses that cause degranulation. These results suggest that activation of a protein kinase, such as PKC, may be responsible for signaling the polymerization of actin in RBL cells and that a rise in intracellular Ca++ is neither necessary nor sufficient for this response.