Proteomics and Phosphoproteomic Analysis to Identify Spleen of Takifugu rubripes Infected Cryptocaryon irritans

Marine Biotechnology - Takifugu rubripes is important commercially fish species in China and it is under serious threat from white spot disease (cyptocaryoniasis), which leads to heavy economic...     

Higher-order interactions of Bcr-Abl can broaden chronic myeloid leukemia (CML) drug repertoire

Bcr-Abl, a nonreceptor tyrosine kinase, is associated with leukemias, especially chronic myeloid leukemia (CML). Deletion of Abl's N-terminal region, to which myristoyl is linked, renders the Bcr-Abl fusion oncoprotein constitutively active. The substitution of Abl's N-terminal region by Bcr enables Bcr-Abl oligomerization. Oligomerization is critical: it promotes clustering on the membrane, which is essential for potent MAPK signaling and cell proliferation. Here we decipher the Bcr-Abl specific, step-by-step oligomerization process, identify a specific packing surface, determine exactly how the process is structured and identify its key elements. Bcr's coiled coil (CC) domain at the N-terminal controls Bcr-Abl oligomerization. Crystallography validated oligomerization via Bcr-Abl dimerization between two Bcr CC domains, with tetramerization via tight packing between two binary assemblies. However, the structural principles guiding Bcr CC domain oligomerization are unknown, hindering mechanistic understanding and drugs exploiting it. Using molecular dynamics (MD) simulations, we determine that the binary complex of the Bcr CC domain serves as a basic unit in the quaternary complex providing a specific surface for dimer–dimer packing and higher-order oligomerization. We discover that the small α1-helix is the key. In the binary assembly, the helix forms interchain aromatic dimeric packing, and in the quaternary assembly, it contributes to the specific dimer–dimer packing. Our mechanism is supported by the experimental literature. It offers the key elements controlling this process which can expand the drug discovery strategy, including by Bcr CC-derived peptides, and candidate residues for small covalent drugs, toward quenching oligomerization, supplementing competitive and allosteric tyrosine kinase inhibitors.     

Sub-Cellular Distribution of Zinc in Different Vegetative Organs and Their Contribution to Grains Zinc Accumulation in Rice Under Different Nitrogen and Zinc Supply

Journal of Plant Growth Regulation - Zinc is an important micronutrient for the growth and development of human body and plants. Proper use of nitrogen fertilizer and foliar application of Zn have...     

Redescription of the Chengjiang arthropod Squamacula clypeata Hou and Bergström, from the Lower Cambrian, south-west China

The anatomy of the arthropod Squamacula clypeata Hou and Bergström, 1997 from the Lower Cambrian Chengjiang Lagersta¨tte is redescribed based on four newly excavated specimens. The new material was collected from localities recently discovered in the Kunming area, Yunnan Province, south-west China, and preserves remarkable details of the ventral morphology, revealed by preparation. Squamacula clypeata is dorsoventrally flattened and rounded in outline. The cephalon was covered by a wide, short shield, with a large doublure and a pair of uniramous antennae on the ventral side. The thorax consists of nine somites, each protected by a tergite and carrying at least one pair of biramous limbs. The pygidium is covered with a small rounded tergum. The endopod is segmented, equipped with short spines on the inner margin of the coxa and a claw-like structure distally, and the exopod flap-like, fringed with setae. The limbs in the pygidium are like those in the thorax in shape. Squamacula was most probably a nektobenthic predator. The spinose endopod could walk, grasp and grind. The large flap-like exopod was adapted for swimming and respiration. Its affinities lie with the Arachnomorpha, but the relationships with other known taxa remain ambiguous.     

Enhancement of CO2 tolerance of Chlorella vulgaris by gradual increase of CO2 concentration

Summary Chlorella vulgaris UTEX259 was cultivated using two different methods of gas supply. In one method the CO₂ concentration in bubbled gas was held constant and in the other method it was increased gradually. Algal growth was almost linear after a short period of lag phase in both methods. With the constant CO₂ concentration, the CO₂ fixation rate in the linear growth phase decreased over 10%(v/v) CO₂, while the rate increased up to 6% CO₂. However, the rate was enhanced by using the latter incremental increase method, especially under a higher concentration of CO₂. The maximum rate of CO₂ fixation was 52 mg CO₂/l·h at 20% CO₂ during the gradual increase of CO₂ concentration.     

RT－cDNA克隆－PCR法获取犬瘟热病毒融合蛋白基因（F）

纯化鸡胚成纤维细胞培养的犬瘟热病毒（ＣａｎｉｎｅＤｉｓｔｅｍｐｅｒＶｉｒｕｓ,ＣＤＶ）,获得病毒基因组ＲＮＡ后,反转录合成双链病毒Ｆ基因ｃＤＮＡ。将此双链ｃＤＮＡ平端插入ＰＵＣ１９质粒ＳａｍⅠ位点构建重组质粒,进行ｃＤＮＡ克隆。以重组克隆质粒为模板ＰＣＲ扩增,获得ＣＤＶ全长Ｆ基因。将此Ｆ基因插入表达载体ＰＢＶ２２０,在大肠杆菌中表达,通过对表达产物的最终鉴定,可确认所获片段为ＣＤＶ全长Ｆ基因．     

Ce~（3＋）与G－肌动蛋白结合引起的构象变化及对聚合的影响

用Ａｅｄａｎｓ标记肌动蛋白单体Ｇ－Ａｃｔｉｎ上Ｃｙｓ３７４残基作为探针,研究了稀土离子Ｃｅ~（３＋）与Ｇ－Ａｃｔｉｎ的结合及引起的微构象变化。Ｃｅ~（３＋）在低浓度（Ｃｅ~（３＋）／Ａｃｔｉｎ摩尔比＜１）和Ｃａ~（２＋）竞争Ｇ－Ａｃｔｉｎ上二价离子的高亲合位点。Ｃｅ~（３＋）取代Ｃａ~（２＋）引起Ａｅｄａｎｓ荧光强度增强与Ｍｇ~（２＋）取代Ｃａ~（２＋）的结果相同。Ｃｅ~（３＋）／Ａｃｔｉｎ＞ｌ则导致Ａｅｄａｎｓ荧光强度下降。说明Ｃｅ~（３＋）在高低两种浓度条件下结合的位点及对Ｃｖｓ３７４的微构象的影响不同。时间分辩测得的Ａｅｄａｎｓ荧光寿命也支持这一结论。ＣＤ谱结果表明Ｃｅ~（３＋）／Ａｃｔｉｎ＜０．４,Ａｃｔｉｎ的二级结构增加,大于０．４又导致其失去。Ｃｅ~（３＋）－Ａｃｔｉｎ在有／无游离ＡＴＰ时用聚合液诱导的聚合结果表明,无游离ＡＴＰ时,极低浓度Ｃｅ~（３＋）促进聚合,高浓度虽有促进但有所减弱;有游离ＡＴＰ时,Ｃｅ~（３＋）／Ａｃｔｉｎ在实验范围内促进聚合。     

人胸腺素α原cDNA的克隆及在大肠杆菌中的表达

采用基因工程方法制取人胸腺素α原获得成功。用２０ｕｇ／ｍｌ植物血球凝集素（ＰＨＡ）和５００Ｕ／ｍｌ重组人白细胞介素２（ＩＬ－２）联合刺激人胎儿胸腺细胞,从中提取总ＲＮＡ,经反转录ＰＣＲ获得了人胸腺素α原ｃＤＮＡ;将之克隆入ｐＵＣ１９中,序列测定表明与已报道序列一致,进一步将之亚克隆入原核表达载体ｐＢＶ２２０,转化大肠杆菌ＤＨ５ａ．观察到在不改变氨基酸编码的前提下,增加胸腺素ａ原上游引物中Ａ、Ｔ含量,可以明显提高胸腺素α原的表达量,同时,不同培养基对它的表达也有影响。胸腺素α原在大肠杆菌中以可溶形式表达,不需复性。初步活性测定显示,它可明显刺激人外周血淋巴细胞Ｅ－玫瑰花结形成率。重组人胸腺素α原在大肠杆菌中表达,为其临床应用及基础研究奠定了基础。     

艾滋病合并隐球菌感染17例尸检材料的临床病理学研究

在１５１例艾滋病尸检材料中发现１７例合并隐球菌感染,均经病理学确诊,患者男１５名,女２名,平均４３．６岁。１２例发生脑膜炎、肺炎和淋巴结炎各７例,尚见脾（６例）、肾（５例）等器官受累。９例为播散性感染。病变为慢性肉牙肿性,其中见有隐球菌。本文描述隐球菌性脑膜炎、肺炎等临床病理学表现,并讨论其病变特征与病理诊断问题。