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《中国细胞生物学学报》2017,(2)
染色质地貌和细胞代谢对细胞命运决定有着重要的作用,但人们对它们之间的互相作用却了解甚少。我们运用基因组范围的si RNA筛选,发现PHB对于维持人胚胎干细胞的自我更新具有重要的作用。其具体机制如下:PHB可以和H3.3的伴侣蛋白HIRA形成蛋白复合体;与PHB相似的是,HIRA对人胚胎干细胞特性的维持也起着重要的作用;特别是PHB和HIRA对异柠檬酸脱氢酶启动子区域染色质结构的调节,调控着对胚胎干细胞命运有着重要作用的代谢产物—α-酮戊二酸的产生。我们的研究揭示了在人胚胎干细胞的细胞核中,PHB通过与HIRA复合体相互作用参与维持正常染色质的结构和重要代谢产物的生成,进而使人胚胎干细胞处于自我更新状态。 相似文献
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植物β-1,3-葡聚糖酶及其基因 总被引:9,自引:0,他引:9
β 1 ,3 葡聚糖酶属PR 2类蛋白 ,能催化真菌细胞壁的重要成分-β 1 ,3 葡聚糖和 β 1 ,3 1 ,6 葡聚糖的水解 ,水解的寡糖产物是植物防御反应的重要激发子。β 1 ,3 葡聚糖酶在植物抵抗真菌病害中发挥着不可忽视的作用 ,关于 β 1 ,3 葡聚糖酶特别是其作用机制和基因表达调控的研究取得了突出进展。β 1 ,3 葡聚糖酶基因和其它抗病相关基因的综合利用将成为植物抗真菌基因工程的有效途径。 相似文献
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氮是蛋白质的基本组成元素,因此氮素循环是维持生物圈的重要条件.脱氮早在一百多年前即已被人们所认识,它是化合态氮转变成游离态氮从而构成氮素循环的主要途径,故被认为是生物学氮循环中的关键过程之一.脱氮作用日益受到重视的主要原因有:1.脱氮引起土壤肥力丧失;2.脱氮作用产生的一氧化氮和一氧化二氮与大气中的二氧化碳、甲烷等一起成为对臭氧层破坏和全球变暖有重要影响的因子之一;3.脱氮在废水处理中起着重要作用.微生物脱氮既可去除过量的硝酸根,又刺激BOD的去除,因此,它对河流海域日益严重的富营养化的治理有着重要… 相似文献
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In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980. 相似文献
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N. P. Vesselkin Yu. V. Natochin 《Journal of Evolutionary Biochemistry and Physiology》2010,46(6):592-603
Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms.
The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal
mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization
followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The
mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction
of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms
are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning
of physiological systems and organs of the living organism 相似文献
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