N-乙酰氨基葡萄糖化在信号转导中的作用

蛋白质磷酸化在生命活动以及信号转导过程中的重要作用已经被研究证实,但不少研究发现在大多数核,胞液蛋白质上不仅存在磷酸化动态修饰,还存在广泛的动态N－乙酰氨基葡萄糖修饰,N－乙酰氨基葡萄糖基转移酶和N－乙酰氨基葡萄糖基酶以类似于蛋白质激酶和磷酸酶的方式调节蛋白质是否发生N－乙酰氨基葡萄糖化。N－乙酰氨基葡萄糖化蛋白质主要分布在细胞核与胞液,其生理功能涉及细胞基本生命活动和调节信号传递。N－乙酰氨基葡萄糖的作用基础与阻断或影响蛋白质的磷酸化有关。     

Identification of domain required for catalytic activity of auxilin in supporting clathrin uncoating by Hsc70

During clathrin-mediated endocytosis Hsc70, supported by the J-domain protein auxilin, uncoats clathrin-coated vesicles. Auxilin contains both a clathrin-binding domain and a J-domain that binds Hsc70, and it has been suggested that these two domains are both necessary and sufficient for auxilin activity. To test this hypothesis, we created a chimeric protein consisting of the J-domain of auxilin linked to the clathrin-binding domain of the assembly protein AP180. This chimera supported uncoating, but unlike auxilin it acted stoichiometrically rather than catalytically because, like Hsc70, it remained associated with the uncoated clathrin. This observation supports our proposal that Hsc70 chaperones uncoated clathrin by inducing formation of a stable Hsc70-clathrin-AP complex. It also shows that Hsc70 acts by dissociating individual clathrin triskelions rather than cooperatively destabilizing clathrin-coated vesicles. Because the chimera lacks the C-terminal subdomain of the auxilin clathrin-binding domain, it seemed possible that this subdomain is required for auxilin to act catalytically, and indeed its deletion caused auxilin to act stoichiometrically. In contrast, deletion of the N-terminal subdomain weakened auxilin-clathrin binding and prevented auxilin from polymerizing clathrin. Therefore the C-terminal subdomain of the clathrin-binding domain of auxilin is required for auxilin to act catalytically, whereas the N-terminal subdomain strengthens auxilin-clathrin binding.     

3D-QSAR studies of checkpoint kinase 1 inhibitors based on molecular docking and CoMFA

Three-dimensional quantitative structure–activity relationship (3D-QSAR) studies were performed on a series of substituted 1,4-dihydroindeno[1,2-c]pyrazoles inhibitors, using molecular docking and comparative molecular field analysis (CoMFA). The docking results from GOLD 3.0.1 provide a reliable conformational alignment scheme for the 3D-QSAR model. Based on the docking conformations and alignments, highly predictive CoMFA model was built with cross-validated q ² value of 0.534 and non-cross-validated partial least-squares analysis with the optimum components of six showed a conventional r ² value of 0.911. The predictive ability of this model was validated by the testing set with a conventional r ² value of 0.812. Based on the docking and CoMFA, we have identified some key features of the 1,4-dihydroindeno[1,2-c]pyrazoles derivatives that are responsible for checkpoint kinase 1 inhibitory activity. The analyses may be used to design more potent 1,4-dihydroindeno[1,2-c]pyrazoles derivatives and predict their activity prior to synthesis.     

Molecular Cloning of Novel Cellulase Genes <Emphasis Type="Italic">cel</Emphasis>9A and <Emphasis Type="Italic">cel</Emphasis>12A from <Emphasis Type="Italic">Bacillus licheniformis</Emphasis> GXN151 and Synergism of Their Encoded Polypeptides

A thermophilic bacterial strain GXN151 which could degrade Avicel efficiently was isolated and identified as Bacillus licheniformis. A genomic library of GXN151 was constructed and two novel endoglucanase genes designated cel9A and cel12A were isolated by screening the library on carboxylmethyl cellulase indicator plates. The analysis of amino acid sequences deduced from the genes indicated that Cel9A consisted of a catalytic domain belonging to glycosyl hydrolase family 9, a linker domain, and a carbohydrate binding module family 3 from N-terminal to C-terminal; Cel12A had only one catalytic domain belonging to glycosyl hydrolase family 12. The combinations of Cel9A and Cel12A produced by the recombinant E. coli exhibited synergistic action against substrates of carboxylmethyl cellulose as well as Avicel.     

Stress-induced RNASET2 overexpression mediates melanocyte apoptosis via the TRAF2 pathway in vitro

The recent genome-wide association study identified a link between vitiligo and genetic variants in the ribonuclease T2 (RNASET2) gene; however, the functional roles of RNASET2 in vitiligo pathogenesis or in melanocyte apoptosis have yet to be determined. The current study was designed to investigate the vitiligo-related expression pattern of RNASET2 and its molecular function involving apoptosis-related signaling proteins and pathways. The results showed overexpression of RNASET2 in epidermis specimens from 40 vitiligo patients compared with that from matched healthy controls. In addition, in vitro analyses indicated that overexpression of RNASET2 was inducible in cultured primary human melanocytes and keratinocytes by stress conditions, that is, exposure to UV irradiation, hydrogen peroxide, and inflammatory factors, respectively, and led to increased cell apoptosis via the tumor necrosis factor receptor-associated factor 2 (TRAF2)–caspases pathway through the physical interaction of RNASET2 with TRAF2. Thus, RNASET2 may contribute to vitiligo pathogenesis by inhibiting TRAF2 expression and, as such, RNASET2 may represent a potential therapeutic target of vitiligo.     

乏情和发情初产母猪下丘脑–垂体–卵巢轴中lincRNAs表达谱比较分析

初产母猪断奶后能否正常发情对养猪生产影响重大,也是初产母猪被淘汰的主要原因。本研究以乏情和发情初产母猪为研究对象,首次利用RNA-seq技术对其下丘脑-垂体-卵巢轴中的基因间长链非编码RNAs(long intergenic noncoding RNAs,lincRNAs)进行筛选比较,得到lincRNAs的表达图谱,并对其特征和功能进行了初步分析。结果显示,在乏情和发情初产母猪下丘脑–垂体–卵巢轴中鉴定得到3519个lincRNAs,以发情组为对照共有17个lincRNAs存在差异表达,其中12个表达上调,5个表达下调(FC≥2,P<0.05)。选择4个差异表达的lincRNAs经qRT-PCR验证,其表达水平与测序结果基本一致。对这17个差异表达的lincRNAs进行GO分析、KEGG通路分析及lincRNA-mRNA共表达网络分析,发现这些lincRNAs主要与猪卵母细胞减数分裂成熟、卵巢细胞分化及颗粒细胞凋亡等生殖活动相关。本研究结果丰富了猪lincRNAs数据资源,为进一步深入研究初产母猪的生殖机能提供了理论依据。     

中国西藏种子植物区系新资料

本文报道了采自西藏喜马拉雅南坡的8个中国种子植物新记录种以及1个西藏新记录属。前者分别是吉隆牛奶菜(Marsdenia roylei)、塔基棕榈(Trachycarpus takil)、喀西蜂斗草(Sonerila khasiana)、旋花锡生藤(Cissampelos convolvulacea)、吉隆角盘兰(Herminium edgeworthii)、尼泊尔西番莲(Passiflora napalensis)、椭穗姜花(Hedychium ellipticum)和藏南象牙参(Roscoea brandisii); 1个西藏新记录属为箭药藤属(Belostemma) (箭药藤 Belostemma hirsutum)。凭证标本存放于中国科学院西双版纳热带植物园标本馆(HITBC)和西藏自治区高原生物研究所标本室(XZ)。     

水稻大粒种质资源和遗传分析

谷粒重量是构成产量的三要素之一, 对提高水稻产量具有重要意义。本文概述了国内外水稻大粒种质资源的现状, 同时对粒重基因遗传分析的研究进展进行了综述。粒重是一个受多基因控制的数量性状, 目前定位的粒重数量性状位点至少达89个、精细定位1个粒重基因gw3.1和１个长粒基因Lk-4(t)以及克隆1个粒重基因GS3, 并在此基础上讨论了粒重在育种上的应用。