ISP1-anchored Polarization of GCβ/CDC50A Complex Initiates Malaria Ookinete Gliding Motility

该工作历时四年，由博士毕业生高涵（第一作者）、博士生杨振科和王旭（共同第一作者）、硕士生钱鹏戈和洪仁杰完成；袁晶教授为通讯作者；厦门大学为第一完成单位。 该工作揭示了疟疾病原疟原虫通过媒介按蚊传播过程中的关键步骤---控制动合子运动的环磷酸鸟苷cGMP信号的激活机制。 疟原虫属于顶复体亚门原生动物，每年导致数亿人口感染疟疾和超过40万病人死亡。疟原虫通过雌性按蚊在哺乳动物宿主间传播。疟疾病人被按蚊叮咬吸血，疟原虫雌雄配子在按蚊消化道中受精形成合子，进一步变形发育为具有运动能力的新月形动合子。只有获得运动能力的动合子，才能穿越按蚊消化道单层上皮细胞，成功感染按蚊媒介。在本研究中，通过大量基因修饰模型，发现GCβ缺失导致动合子运动完全丢失，进而失去按蚊感染和传播能力。研究还发现，GCβ由细胞质均匀分布改变为在动合子顶体突出一侧聚集，并且GCβ聚集和动合子成熟完全同步，显示GCβ聚集可能直接激活cGMP信号。 本工作还发现GCβ结合蛋白CDC50A，后者承担分子伴侣功能，在动合子转化和成熟动合子中，稳定GCβ。此外，进一步筛选发现动合子内膜复合物蛋白ISP1，能够结合和锚定GCβ/CDC50A复合物，在成熟动合子中维持复合物的聚集。本研究为深入开展寄生性原生动物的发育转化和信号调控提供了线索和借鉴。【Abstract】Ookinete gliding motility is essential for penetration of the mosquito midgut wall and transmission of malaria parasites. Cyclic guanosine monophosphate (cGMP) signaling has been implicated in ookinete gliding. However, the upstream mechanism of how the parasites activate cGMP signaling and thus initiate ookinete gliding remains unknown. Using real-time imaging to visualize Plasmodium yoelii guanylate cyclase β (GCβ), we show that cytoplasmic GCβ translocates and polarizes to the parasite plasma membrane at “ookinete extrados site” (OES) during zygote to ookinete differentiation. The polarization of enzymatic active GCβ at OES initiates gliding of matured ookinete. Both the P4-ATPase-like domain and guanylate cyclase domain are required for GCβ polarization and ookinete gliding. CDC50A, a co-factor of P4-ATPase, binds to and stabilizes GCβ during ookinete development. Screening of inner membrane complex proteins identifies ISP1 as a key molecule that anchors GCβ/CDC50A complex at the OES of mature ookinetes. This study defines a spatial-temporal mechanism for the initiation of ookinete gliding, where GCβ polarization likely elevates local cGMP levels and activates cGMP-dependent protein kinase signaling.We thank Dr. David Baker (London School of Hygiene and Tropical Medicine) for his comments on this manuscript. This work was supported by the National Natural Science Foundation of China (81522027, 31772443, and 31501912), the Fundamental Research Funds for the Central Universities (20720160069, 20720150165, and 2013121033), the China's 1000 Young Talents Program, the “111” Project of the Ministration of Education of China (B06016), and the Division of Intramural Research, National Institute of Allergy and Infectious Diseases (NIAID), NIH (X.S.). The authors thank Cindy Clark, NIH Library Writing Center, for manuscript editing assistance. 该研究得到国家自然科学基金委、中组部“青年千人计划”和厦门大学校长基金的资助

Extraction of V(V) and Cr(VI) from aqueous solution using primary amine extractants: extraction mechanism and oxidation of extractants

The extraction mechanism and the oxidation of extractants are essential to optimize the extraction process. To investigate the two problems for selective extraction of V(V) and Cr(VI), the extraction complexes of V(V) and Cr(VI) formed in the process of extraction with primary amines were obtained by solvent-out crystallization, respectively. The average compositions of the extraction complexes were determined by element analysis, X-ray photoelectron spectroscopy, and inductive couple plasma-optical emission spectrometry. The chemical functional groups of the extraction complexes were confirmed by Fourier transform infrared spectroscopy and Raman spectroscopy. The structures of the extraction complexes of V(V) were speculated with their functional groups and average compositions. The hydrogen bond association mechanism of V(V) extraction was illustrated with the structure of the complexes, and the oxidation reaction of extractants with Cr(VI) was also demonstrated. According to the oxidation reaction of extractants with Cr(VI) and experiment conditions for the initial pH value, the optimized operation condition of the initial pH value &gt;= 5.5 was determined to prevent the oxidation of extractants. The interaction of V(V) and Cr(VI) for the vanadium extraction and extractant oxidation was also investigated.</p

High-efficient extraction of vanadium and its application in the utilization of the chromium-bearing vanadium slag

The high-efficient extraction of vanadium using primary amine and its application in the utilization of the chromium-bearing vanadium slag (V-Cr slag) were studied in this work. The extraction mechanism and the possible difficulties in the application were both considered. From the results, the extraction percentage of vanadium using free primary amine with the hydrogen bond association mechanism is higher than that in the acidic environment by primary amine salts. The inorganic ions and other impurities existing in the system were all considered to research for the continuous operation of the extraction. Furthermore, the viscosities of the fresh organic phase and the recycled organic phase were determined using the extractant not only N1923 but also LK-N21, where the viscosity of the latter system increased slightly during the recycled process of the extractant. Based on the above results, the pilot and the commercial experiment were carried out. In the large-scale experiment, the vanadium was extracted and the product of 99.5 wt.% vanadium pentoxide was obtained, and the mass loss of the extractant was only 0.1%. (C) 2016 Published by Elsevier B.V

Trusted Data Storage Architecture for National Infrastructure

National infrastructure is a material engineering facility that provides public services for social production and residents&rsquo; lives, and a large-scale complex device or system is used to ensure normal social and economic activities. Due to the problems of difficult data collection, long project period, complex data, poor security, difficult traceability and data intercommunication, the archives management of most national infrastructure is still in the pre-information era. To solve these problems, this paper proposes a trusted data storage architecture for national infrastructure based on blockchain. This consists of real-time collection of national infrastructure construction data through sensors and other Internet of Things devices, conversion of heterogeneous data source data into a unified format according to specific business flows, and timely storage of data in the blockchain to ensure data security and persistence. Knowledge extraction of data stored in the chain and the data of multiple regions or fields are jointly modeled through federal learning. The parameters and results are stored in the chain, and the information of each node is shared to solve the problem of data intercommunication

Separation of V(V) and Cr(VI) in leaching solution using annular centrifugal contactors

The effective V(V) and Cr(VI) separation is very difficult due to their similarity in physiochemical properties. In this research, almost completely separation of V(V) and Cr(VI) with primary amine N1923 was firstly demonstrated by employing multistage countercurrent extraction (MCE) with annular centrifugal contactors (ACCs). The optimum operation conditions of single-stage extraction with ACC were determined by systematic experiments, and best conditions of the rotor speed, the flow rate and the flow ratio of organic phase to aqueous phase were obtained. The loaded-organic phase can be reused for extraction process after stripping with ammonia/sodium hydroxide. Vanadium, in the leaching/aqueous solution with the initial pH of 6.1, was reached to extraction equilibrium by three-stage countercurrent extraction with ACCs. V(V) and Cr(VI) were separated through 21 stages of countercurrent extraction with ACCs. 95.1% of vanadium and almost none of chromium were extracted, with the separation factor approaching infinity. Through the mechanism of hydrogen bond association and different species of two metals in the leaching/aqueous solution, an in-depth analysis to correlate the results obtained and the chemical reactions with ACCs has been made in order to establish a firm conclusion with aim of the guidance in industrial application.(C) 2017 Elsevier B.V. All rights reserved.</p

Comparison of Two Solvent Extraction Systems for the Separation of V(V) and Cr(VI) from an Industrial Leaching Solution

Two solvent extraction systems for V (V) and Cr (VI) separation in leaching solution were investigated in order to select the suitable separation method for the disposing of chromium-bearing vanadium slag. The best/suitable system was determined by extraction yield (E-V,%) and the separation factor of V(V) and Cr(VI) ((V/Cr)). On the condition of 1:1 molar ratio of H+ to vanadium (V), the E-V values were 99.8% and 95.1%, while the (V/Cr) values were 546.58 and 29.53 using the two different systems, respectively. The extraction reactions for system 1 were determined by the slope method, and the chemical equilibrium constants were obtained.</p

Rapid selective extraction of V(V) from leaching solution using annular centrifugal contactors and stripping for NH4VO3

The efficient and rapid selective extraction of V(V) from leaching solution with sulfated primary amine N1923 was demonstrated. In the single-stage extraction using annular centrifugal contactor (ACC), the influence of the total flow and the speed rotor on extraction percentage of V(V) was investigated using central composite design (CCD), and the results of experimental conditions were analyzed by analysis of variance. The current concentrations of V(V) and Cr(VI) in leaching solution were 23.70g/L and 1.52g/L, respectively. 99.6% of vanadium was extracted and separated from the aqueous solution by employing four-stage countercurrent extraction with annular centrifugal contactors (ACCs). The total contact/resident time of the two phases was 4.8 min, and the separation factor of V(V) and Cr(VI) was 273.9. The two metals in leaching solution can be separated primarily, and then 23.61g/L V(V) and 0.72g/L Cr(VI) in loaded organic phase can be further separated by the stripping. The NH4VO3 with purity of 99.7% was obtained by two steps of separations and studied by the analyses of XRD, SEM and particle size distribution (PSD). The reactions of extraction and stripping in the separation processes were investigated in order to establish a firm conclusion. (C) 2017 Published by Elsevier B.V.</p

Measurements and correlation of liquid-liquid equilibrium data for the ternary (3-heptanone plus phenol plus water) system

Liquid-liquid equilibrium (LLE) for the ternary (3-heptanone + phenol + water) system has been determined under atmospheric pressure at 298.15 K, 303.15 K, 318.15 K and 323.15 K. The NRTL and UNIQUAC models were used to correlate the experimental results. The corresponding binary parameters were obtained and their physical meaning is explained by intermolecular attractive energy. The results from the two models agree well with experimental values, The NRTL model was more accurate than that of the UNIQUAC model. Meanwhile, the NRTL model was used to regress all the experimental values at different temperatures simultaneously, which is defined as total-regression. Compared with the individual regression by the NRTL model, the total regression by the NRTL model has fewer parameters and covers a wider interpolated range from 298.15 K to 323.15 K. The distribution coefficient for phenol changes with temperature. The phenol concentration can be expressed as a function of activity coefficient of phenol in both phases. The effect of temperature on the extraction performance of 3-heptanone was also investigated. The phenol extraction process by 3-heptanone is exothermic. The increase of temperature is not a benefit to phenol extraction. (C) 2016 Published by Elsevier Ltd.</p