C1q is the first subcomponent of classical pathway in the complement system and a major link between innate and acquired immunities. The globular （gC1q） domain similar with C1q was also found in many non-complement ...C1q is the first subcomponent of classical pathway in the complement system and a major link between innate and acquired immunities. The globular （gC1q） domain similar with C1q was also found in many non-complement C1q-domain-containing （C1qDC） proteins which have similar crystal structure to that of the multifunctional tumor necrosis factor （TNF） ligand family, and also have diverse functions. In this study, we identified a total of 52 independent gene sequences encoding C1q-domain-containing proteins through comprehensive searches of zebrafish genome, cDNA and EST databases. In comparison to 31 orthologous genes in human and different numbers in other species, a significant selective pressure was suggested during vertebrate evolution. Domain organization of C1q-domain-containing （C1qDC） proteins mainly includes a leading signal peptide, a collagen-like region of variable length, and a C-terminal C1q domain. There are 11 highly conserved residues within the C1q domain, among which 2 are invariant within the zebrafish gene set. A more extensive database searches also revealed homologous C1qDC proteins in other vertebrates, invertebrates and even bacterium, but no homologous sequences for encoding C1qDC proteins were found in many species that have a more recent evolutionary history with zebrafish. Therefore, further studies on C1q-domain-containing genes among different species will help us understand evolutionary mechanism of innate and acquired immunities.展开更多
Binding sialates to hemagglutinin-neuramini- dase (HN) activates (triggers) the fusion protein (F) to start the membrane fusion process of paramyxovirus, but the mechanism by which the HN and F associate with each oth...Binding sialates to hemagglutinin-neuramini- dase (HN) activates (triggers) the fusion protein (F) to start the membrane fusion process of paramyxovirus, but the mechanism by which the HN and F associate with each other to induce membrane fusion is still unclear. It is noteworthy to study the interaction domains of HN and F of paramyxovirus. To screen interacting domains of the HN and F proteins of Avian parainfluenza virus-2 (APIV-2) and identify the struc- ture of binding proteins, the GST pull-down assay and mass spectroscopy (MS) and circular dichroism (CD) experiments were performed in this study. The study revealed that the globular head region of HN protein tends to form a complex with either the heptad repeat 1 (HR1) or the heptad repeat 2 (HR2) of F protein respectively. This paper discusses the novel fusion mechanism induced by paramyxovirus HN and F proteins.展开更多
将3T3-L1前脂肪细胞诱导分化为成熟的脂肪细胞，用软脂酸制备脂肪细胞胰岛素抵抗模型，不同浓度的脂联素球状结构域（globular domain of adiponectin，gAd）干预已经产生胰岛素抵抗的3T3-L1脂肪细胞，葡萄糖氧化酶法检测培养液中葡萄...将3T3-L1前脂肪细胞诱导分化为成熟的脂肪细胞，用软脂酸制备脂肪细胞胰岛素抵抗模型，不同浓度的脂联素球状结构域（globular domain of adiponectin，gAd）干预已经产生胰岛素抵抗的3T3-L1脂肪细胞，葡萄糖氧化酶法检测培养液中葡萄糖的消耗量，实时荧光定量PCR法检测胰岛素受体底物（1RS）-1、磷脂酰肌醇3激酶（P13K）、蛋白激酶B（PKB）基因水平的变化，Western印迹检测IRS-1酪氨酸磷酸化水平。结果显示，与对照组相比，各实验组葡萄糖消耗量均显著增加（P〈0．01），且随着gAd浓度的增加．葡萄糖消耗量也逐渐增加；500ng／mlgAd组及1000ng／mlgAd组IRS—1、P13K、PKB的mRNA表达均比对照组显著增加（P〈0．05）；同时，gAd可增加3T3-L1脂肪细胞胰岛素抵抗模型IRS-1酪氨酸磷酸化水平，且呈浓度依赖性．提示gAd能够促进3T3-LI脂肪细胞胰岛素抵抗模型葡萄糖的摄取，其机制可能与促进脂肪细胞胰岛素信号转导、改善胰岛素抵抗有关。展开更多
基金Acknowledgements This work was supported by the National Major Basic Research Program （No. 2004CB117401）；by the National Natural Science Foundation of China （No. 90408013）.
文摘C1q is the first subcomponent of classical pathway in the complement system and a major link between innate and acquired immunities. The globular （gC1q） domain similar with C1q was also found in many non-complement C1q-domain-containing （C1qDC） proteins which have similar crystal structure to that of the multifunctional tumor necrosis factor （TNF） ligand family, and also have diverse functions. In this study, we identified a total of 52 independent gene sequences encoding C1q-domain-containing proteins through comprehensive searches of zebrafish genome, cDNA and EST databases. In comparison to 31 orthologous genes in human and different numbers in other species, a significant selective pressure was suggested during vertebrate evolution. Domain organization of C1q-domain-containing （C1qDC） proteins mainly includes a leading signal peptide, a collagen-like region of variable length, and a C-terminal C1q domain. There are 11 highly conserved residues within the C1q domain, among which 2 are invariant within the zebrafish gene set. A more extensive database searches also revealed homologous C1qDC proteins in other vertebrates, invertebrates and even bacterium, but no homologous sequences for encoding C1qDC proteins were found in many species that have a more recent evolutionary history with zebrafish. Therefore, further studies on C1q-domain-containing genes among different species will help us understand evolutionary mechanism of innate and acquired immunities.
基金This work was supported by the National Natural Sciences Foundation of China (Grant No. 30228025)The Founda-tion of China Agricultural University (Grant No. 2004009).
文摘Binding sialates to hemagglutinin-neuramini- dase (HN) activates (triggers) the fusion protein (F) to start the membrane fusion process of paramyxovirus, but the mechanism by which the HN and F associate with each other to induce membrane fusion is still unclear. It is noteworthy to study the interaction domains of HN and F of paramyxovirus. To screen interacting domains of the HN and F proteins of Avian parainfluenza virus-2 (APIV-2) and identify the struc- ture of binding proteins, the GST pull-down assay and mass spectroscopy (MS) and circular dichroism (CD) experiments were performed in this study. The study revealed that the globular head region of HN protein tends to form a complex with either the heptad repeat 1 (HR1) or the heptad repeat 2 (HR2) of F protein respectively. This paper discusses the novel fusion mechanism induced by paramyxovirus HN and F proteins.
文摘将3T3-L1前脂肪细胞诱导分化为成熟的脂肪细胞，用软脂酸制备脂肪细胞胰岛素抵抗模型，不同浓度的脂联素球状结构域（globular domain of adiponectin，gAd）干预已经产生胰岛素抵抗的3T3-L1脂肪细胞，葡萄糖氧化酶法检测培养液中葡萄糖的消耗量，实时荧光定量PCR法检测胰岛素受体底物（1RS）-1、磷脂酰肌醇3激酶（P13K）、蛋白激酶B（PKB）基因水平的变化，Western印迹检测IRS-1酪氨酸磷酸化水平。结果显示，与对照组相比，各实验组葡萄糖消耗量均显著增加（P〈0．01），且随着gAd浓度的增加．葡萄糖消耗量也逐渐增加；500ng／mlgAd组及1000ng／mlgAd组IRS—1、P13K、PKB的mRNA表达均比对照组显著增加（P〈0．05）；同时，gAd可增加3T3-L1脂肪细胞胰岛素抵抗模型IRS-1酪氨酸磷酸化水平，且呈浓度依赖性．提示gAd能够促进3T3-LI脂肪细胞胰岛素抵抗模型葡萄糖的摄取，其机制可能与促进脂肪细胞胰岛素信号转导、改善胰岛素抵抗有关。
