Quarmby L M, Hartzell H C
Department of Physiology, Emory University School of Medicine, Atlanta, Georgia 30322.
J Cell Biol. 1994 Mar;124(5):807-15. doi: 10.1083/jcb.124.5.807.
The molecular machinery of deflagellation can be activated in detergent permeabilized Chlamydomonas reinhardtii by the addition of Ca2+ (Sanders, M. A., and J. L. Salisbury, 1989. J. Cell Biol. 108:1751-1760). This suggests that stimuli which induce deflagellation in living cells cause an increase in the intracellular concentration of Ca2+, but this has never been demonstrated. In this paper we report that the wasp venom peptide, mastoparan, and the permeant organic acid, benzoate, activate two different signalling pathways to trigger deflagellation. We have characterized each pathway with respect to: (a) the requirement for extracellular Ca2+; (b) sensitivity to Ca2+ channel blockers; and (c) 45Ca influx. We also report that a new mutant strain of C. reinhardtii, adf-1, is specifically defective in the acid-activated signalling pathway. Both signalling pathways appear normal in another mutant, fa-1, that is defective in the machinery of deflagellation (Lewin, R. and C. Burrascano. 1983. Experientia. 39:1397-1398; Sanders, M. A., and J. L. Salisbury. 1989. J. Cell Biol. 108:1751-1760). We conclude that mastoparan induces the release of an intracellular pool of Ca2+ whereas acid induces an influx of extracellular Ca2+ to activate the machinery of deflagellation.
通过添加Ca2+，去鞭毛的分子机制可以在经去污剂通透处理的莱茵衣藻中被激活（桑德斯，M. A.，和J. L. 索尔兹伯里，1989年。《细胞生物学杂志》108:1751 - 1760）。这表明在活细胞中诱导去鞭毛的刺激会导致细胞内Ca2+浓度升高，但这从未得到证实。在本文中，我们报告黄蜂毒液肽、马斯托帕兰和渗透性有机酸苯甲酸酯激活两种不同的信号通路来触发去鞭毛。我们已经从以下几个方面对每条通路进行了表征：（a）对细胞外Ca2+的需求；（b）对Ca2+通道阻滞剂的敏感性；以及（c）45Ca内流。我们还报告了莱茵衣藻的一个新突变株adf - 1，它在酸激活的信号通路中存在特异性缺陷。在另一个去鞭毛机制存在缺陷的突变体fa - 1中，这两种信号通路看起来正常（莱文，R. 和C. 布拉斯卡诺。1983年。《实验》39:1397 - 1398；桑德斯，M. A.，和J. L. 索尔兹伯里。1989年。《细胞生物学杂志》108:1751 - 1760）。我们得出结论，马斯托帕兰诱导细胞内Ca2+池的释放，而酸诱导细胞外Ca2+内流以激活去鞭毛机制。
