Tai‐Wen Lin  Chi‐Chih Chen  Shu‐Mei Wu  Yu‐Ching Chang  Yi‐Chuan Li  Yu‐Wang Su  Chwan‐Deng Hsiao  Hsin‐Yang Chang 《The Plant journal : for cell and molecular biology》2019,99(1):128-143

In mammals and yeast, tail‐anchored (TA) membrane proteins destined for the post‐translational pathway are safely delivered to the endoplasmic reticulum (ER) membrane by a well‐known targeting factor, TRC40/Get3. In contrast, the underlying mechanism for translocation of TA proteins in plants remains obscure. How this unique eukaryotic membrane‐trafficking system correctly distinguishes different subsets of TA proteins destined for various organelles, including mitochondria, chloroplasts and the ER, is a key question of long standing. Here, we present crystal structures of algal ArsA1 (the Get3 homolog) in a distinct nucleotide‐free open state and bound to adenylyl‐imidodiphosphate. This approximately 80‐kDa protein possesses a monomeric architecture, with two ATPase domains in a single polypeptide chain. It is capable of binding chloroplast (TOC34 and TOC159) and mitochondrial (TOM7) TA proteins based on features of its transmembrane domain as well as the regions immediately before and after the transmembrane domain. Several helices located above the TA‐binding groove comprise the interlocking hook‐like motif implicated by mutational analyses in TA substrate recognition. Our data provide insights into the molecular basis of the highly specific selectivity of interactions of algal ArsA1 with the correct sets of TA substrates before membrane targeting in plant cells.  相似文献   

    

Hongke Luo  Yuchen Guo  Yuting Liu  Yuan Wang  Rixin Zheng  Yu Ban  Lin Peng  Quan Yuan  Weiqing Liu 《Cell proliferation》2019,52(4)

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Shijin Tang  Yinping Pan  Deshuai Lou  Shunlin Ji  Liancai Zhu  Jun Tan  Na Qi  Qiong Yang  Zhi Zhang  Biling Yang  Wenyan Zhao  Bochu Wang 《Protein science : a publication of the Protein Society》2019,28(5):910-919

7α‐Hydroxysteroid dehydrogenase (7α‐HSDH) is an NAD(P)H‐dependent oxidoreductase belonging to the short‐chain dehydrogenases/reductases. In vitro, 7α‐HSDH is involved in the efficient biotransformation of taurochenodeoxycholic acid (TCDCA) to tauroursodeoxycholic acid (TUDCA). In this study, a gene encoding novel 7α‐HSDH (named as St‐2‐1) from fecal samples of black bear was cloned and heterologously expressed in Escherichia coli. The protein has subunits of 28.3 kDa and a native size of 56.6 kDa, which suggested a homodimer. We studied the relevant properties of the enzyme, including the optimum pH, optimum temperature, thermal stability, activators, and inhibitors. Interestingly, the data showed that St‐2‐1 differs from the 7α‐HSDHs reported in the literature, as it functions under acidic conditions. The enzyme displayed its optimal activity at pH 5.5 (TCDCA). The acidophilic nature of 7α‐HSDH expands its application environment and the natural enzyme bank of HSDHs, providing a promising candidate enzyme for the biosynthesis of TUDCA or other related chemical entities.  相似文献   

    

Mohammadhossein Hassanshahi  Yu-Wen Su  Samira Khabbazi  Chia-Ming Fan  Qian Tang  Xuesen Wen  Jian Fan  Ke-Ming Chen  Cory J. Xian 《Journal of cellular physiology》2019,234(9):16549-16561

Methotrexate (MTX), a widely used antimetabolite in paediatric cancer to treatment, has been widely reported to cause bone loss and bone marrow (BM) microvascular (particularly sinusoids) damage. Investigations must now investigate how MTX-induced bone loss and microvasculature damage can be attenuated/prevented. In the present study, we examined the potency of icariin, an herbal flavonoid, in reducing bone loss and the dilation/damage of BM sinusoids in rats caused by MTX treatment. Groups of young rats were treated with five daily MTX injections (0.75 mg/kg) with and without icariin oral supplementation until Day 9 after the first MTX injection. Histological analyses showed a significant reduction in the bone volume/tissue volume (BV/TV) fraction (%) and trabecular number in the metaphysis trabecular bone of MTX-treated rats, but no significant changes in trabecular thickness and trabecular spacing. However, the BV/TV (%) and trabecular number were found to be significantly higher in MTX + icariin-treated rats than those of MTX alone-treated rats. Gene expression analyses showed that icariin treatment maintained expression of osteogenesis-related genes but suppressed the induction of adipogenesis-related genes in bones of MTX-treated rats. In addition, icariin treatment attenuated MTX-induced dilation of BM sinusoids and upregulated expression of endothelial cell marker CD31 in the metaphysis bone of icariin + MTX-treated rats. Furthermore, in vitro studies suggest that icariin treatment can potentially enhance the survival of cultured rat sinusoidal endothelial cells against cytotoxic effect of MTX and promote their migration and tube formation abilities, which is associated with enhanced production of nitric oxide.  相似文献   

    

Fangsheng Fu  Siyuan Shao  Ziyi Wang  Fangming Song  Xixi Lin  Jiaxin Ding  Chen Li  Zuoxing Wu  Kai Li  Yu Xiao  Yiji Su  Jinmin Zhao  Qian Liu  Jiake Xu 《Journal of cellular physiology》2019,234(7):11951-11959

Osteoporosis, arthritis, Peget's disease, bone tumor, periprosthetic joint infection, and periprosthetic loosening have a common characteristic of osteolysis, which is characterized by the enhanced osteoclastic bone resorptive function. At present, the treatment target of these diseases is to interfere with osteoclastic formation and function. Scutellarein (Scu), a flavonoids compound, can inhibit the progress of tumor and inflammation. However, the role of Scu in inflammatory osteolysis isn’t elucidated clearly. Our study showed that Scu inhibited bone destruction induced by LPS in vivo and OC morphology and function induced by RANKL in vitro. Mechanistic studies revealed that Scu suppressed osteoclastic marker gene expression by RANKL-induced, such as Ctsk9, Mmp9, Acp5, and Atp6v0d2. In addition, we found that the inhibition effects of osteoclastogenesis and bone resorption function of Scu were mediated via attenuating NF-κB and NFAT signaling pathways. In conclusion, the results showed that Scu may become a potential new drug for the treatment of inflammatory osteolysis.  相似文献   

    

Jun Feng Su  Chun Yu Gao  Ting Lin Huang  Xue Chen Bai  Hai Rong Zhu 《Geomicrobiology journal》2019,36(5):396-404

In this study, the denitrification performance of the mixotrophic biological reactor was investigated under varying Fe(II)/Mn(II) molar ratio conditions. Results indicate that the optimal nitrate removal ratio occurred at an Fe(II)/Mn(II) molar ratio of 9:1, pH of 7, with an HRT of 10?h. When the reactor was performing under optimal conditions, the nitrate removal reached 100.00% at a rate of 0.116?mmol·L^?1·h^?1. The proportion of oxidized Fe(II) and Mn(II) reached 99.29% and 21.88%, respectively. High-throughput sequencing results show that Pseudomonas was the dominant species in the mixotrophic biological reactor. Furthermore, the relative abundance of Pseudomonas and denitrification performance was significantly influenced by variation in the Fe(II)/Mn(II) molar ratio.  相似文献   

    

Z. Wang  Y. Yang  S. Li  K. Li  Z. Tang 《Animal genetics》2019,50(6):660-669

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Makawi Ahmed Abdalhamid Osman  Yu‐Jing Sun  Rui‐Jia Li  Hui Lin  Dong‐Mei Zeng  Xin‐Yu Chen  Dongfang He  Hui‐Wei Feng  Zhao Yang  Jin Wang  Chaodong Wu  Min Cui  Jin‐Peng Sun  Yuqing Huo  Xiao Yu 《Journal of cellular and molecular medicine》2019,23(7):4653-4665

Severe reduction in the β‐cell number (collectively known as the β‐cell mass) contributes to the development of both type 1 and type 2 diabetes. Recent pharmacological studies have suggested that increased pancreatic β‐cell proliferation could be due to specific inhibition of adenosine kinase (ADK). However, genetic evidence for the function of pancreatic β‐cell ADK under physiological conditions or in a pathological context is still lacking. In this study, we crossed mice carrying LoxP‐flanked Adk gene with Ins2‐Cre mice to acquire pancreatic β ‐cell ADK deficiency (Ins2‐Cre^±Adk^fl/fl) mice. Our results revealed that Ins2‐Cre^+/‐Adk^fl/fl mice showed improved glucose metabolism and β‐cell mass in younger mice, but showed normal activity in adult mice. Moreover, Ins2‐Cre^±Adk^fl/fl mice were more resistant to streptozotocin (STZ) induced hyperglycaemia and pancreatic β‐cell damage in adult mice. In conclusion, we found that ADK negatively regulates β‐cell replication in young mice as well as under pathological conditions, such as STZ induced pancreatic β‐cell damage. Our study provided genetic evidence that specific inhibition of pancreatic β‐cell ADK has potential for anti‐diabetic therapy.  相似文献   

    

Sixing Xu  Wenbo Ding  Hengyu Guo  Xiaohong Wang  Zhong Lin Wang 《Liver Transplantation》2019,9(30)

Triboelectric nanogenerator (TENG) which harvests ubiquitous ambient mechanical energy is a promising power source that can meet the distributed energy demand in the internet of things, wearable electronics, etc. However, the available output of TENG is severely limited by the saturated polarized charge density, small intrinsic capacitance, and large matching impedance. Herein, an effective power management strategy is proposed that flips the free charges on the conductive layer through a controlled LC oscillating circuit composed of the diode, switch, inductor, and the intrinsic capacitor of TENG. In this way, the equivalent charge density reaches a level higher than the saturated polarized charge density. The simulation and experiments show that the limit of energy output can be exceeded under arbitrary load resistance, especially for the low‐impedance common electronics. It is believed that such a general, low‐cost, and highly effective strategy can further broaden the applications of TENG devices across the fields and probably be a new performance evaluation standard for TENG.  相似文献   

    

Yiming An  Xia Long  Ming Ma  Jue Hu  He Lin  Dan Zhou  Zheng Xing  Bolong Huang  Shihe Yang 《Liver Transplantation》2019,9(41)

Currently, in addition to the electroactive non‐noble metal water‐splitting electrocatalysts, a scalable synthetic route and simple activity enhancement strategy is also urgently needed. In particular, the well‐controlled synthesis of the well‐recognized metal–metal nanointer face in a single step remains a key challenge. Here, the synthesis of Cu‐supported Ni₄Mo nanodots on MoO_x nanosheets (Ni₄Mo/MoO_x) with controllable Ni₄Mo particle size and d‐band structure is reported via a facile one‐step electrodeposition process. Density functional theory (DFT) calculations reveal that the active open‐shell effect from Ni‐3d‐band optimizes the electronic configuration. The Cu‐substrate enables the surface Ni–Mo alloy dots to be more electron‐rich, forming a local connected electron‐rich network, which boosts the charge transfer for effective binding of O‐related species and proton–electron charge exchange in the hydrogen evolution reaction. The Cu‐supported Ni₄Mo/MoO_x shows an ultralow overpotential of 16 mV at a current density of 10 mA cm^?2 in 1 m KOH, demonstrating the smallest overpotential, at loadings as low as 0.27 mg cm^?2, among all non‐noble metal catalysts reported to date. Moreover, an overpotential of 105 mV allows it to achieve a current density of 250 mA cm^?2 in 70 °C 30% KOH, a remarkable performance for alkaline hydrogen evolution with competitive potential for applications.  相似文献