Derkach K V, Shpakov A O, Uspenskaia Z I, Kuznetsova L A
Tsitologiia. 2009;51(12):1013-8.
Cytoskeleton plays a key role in functioning of hormonal signaling systems in vertebrate animals. The data on the influence of cytoskeleton components, in particular the microtubules, on functional activity of chemosignaling systems of unicellular organisms are absent at the present time. The aim of this work was the study of influence of microtubule-disrupting agents, colchicine and vinblastine, on the adenylyl cyclase (AC) system of free-living ciliate Dileptus anser. The treatment of D. anser with colchicine and vinblastine (10(-5)-10(-6) M) weakly influenced basal activity of AC, but caused essential decrease or complete blocking of AC stimulation by non-hormonal (GppNHp, sodium fluoride) and hormonal (aldrenaline, serotonin, glucagon) agents. As a result of this treatment, a decrease of the basal level of GTP-binding of heterotrimeric G-proteins and inhibition of G-protein stumulation by the hormones were found. In the case of adrenaline it was that colchicine and vinblastine disturb the AC stimulation by the hormone, mediated with the G(s)-protein, but weakly influence its inhibitory AC effect, realized via the G(i)-protein. Thus, it was established for the first time that microtubules in unicellular organisms such as the ciliate D. anser are involved in regulation of functional activity of AC system, and their action is realized at the level of the G-proteins similar to the G(s)-proteins of the vertebrates.
细胞骨架在脊椎动物激素信号系统的功能发挥中起着关键作用。目前尚无关于细胞骨架成分，特别是微管，对单细胞生物化学信号系统功能活性影响的数据。本研究的目的是探讨微管破坏剂秋水仙碱和长春花碱对自由生活的纤毛虫Dileptus anser腺苷酸环化酶（AC）系统的影响。用秋水仙碱和长春花碱（10^(-5)-10^(-6) M）处理D. anser，对AC的基础活性影响较弱，但导致非激素（GppNHp、氟化钠）和激素（肾上腺素、5-羟色胺、胰高血糖素）刺激AC的作用显著降低或完全阻断。这种处理导致异源三聚体G蛋白的GTP结合基础水平降低，以及激素对G蛋白刺激的抑制。就肾上腺素而言，秋水仙碱和长春花碱干扰了由G(s)蛋白介导的激素对AC的刺激，但对通过G(i)蛋白实现的激素对AC的抑制作用影响较弱。因此，首次确定在单细胞生物如纤毛虫D. anser中，微管参与了AC系统功能活性的调节，并且它们的作用在类似于脊椎动物G(s)蛋白的G蛋白水平上得以实现。
