Recognition of the E1kE1f cholinesterase genotype in a family segregating three rare genes, E1k, E1f and E1a

The first identification of the cholinesterase variant E1kE1f is reported from a family study. The evidence is based on the determination of enzymic activity, dibucaine, fluoride and RO2 numbers. Three individuals appear to have this genotype, and family evidence is not at variance with our conclusions. All three individuals will be sensitive to suxamethonium.     

Myc-mediated proliferation and lymphomagenesis,but not apoptosis,are compromised by E2f1 loss

Myc and E2f1 promote cell cycle progression, but overexpression of either can trigger p53-dependent apoptosis. Mice expressing an Emu-Myc transgene in B lymphocytes develop lymphomas, the majority of which sustain mutations of either the Arf or p53 tumor suppressors. Emu-Myc transgenic mice lacking one or both E2f1 alleles exhibited a slower onset of lymphoma development associated with increased expression of the cyclin-dependent kinase inhibitor p27(Kip1) and a reduced S phase fraction in precancerous B cells. In contrast, Myc-induced apoptosis and the frequency of Arf and p53 mutations in lymphomas were unaffected by E2f1 loss. Therefore, Myc does not require E2f1 to induce Arf, p53, or apoptosis in B cells, but depends upon E2f1 to accelerate cell cycle progression and downregulate p27(Kip1).     

戊型肝炎病毒开放读框2的克隆及表达载体的构建

戊型肝炎病毒（HEV）为单股正链RNA病毒,整个基因组有3个开放性阅读框架（ORF）,ORF2（全长约1.98kb）是主要结构基因编码区。将经过PCR获得的ORF2基因插入非分泌型酵母穿梭质粒pPIC3,构成受醇氧化酶（AOX2）的启动子与转录终止区控制的酵母表达质粒,重组质粒经酶切线性化后转化酵母细胞GS115,经过鉴定可挑取与酵母染色体发生交换的重组体,用于进一步的真核表达。     

Rubella virus contains one capsid protein and three envelope glycoproteins, E1, E2a, and E2b.

We have analyzed the structure of rubella virus proteins labeled metabolically with [35S]methionine, [3H]mannose, and [3H]glucosamine or externally with [3H]borohydride after galactose oxidase treatment. Four structural proteins, with MrS of about 58,000 (E1), 47,000 (E2a), 42,000 (E2b), and 33,000 (C), were resolved on sodium dodecyl sulfate-polyacrylamide gels. Tryptic peptide maps obtained from [35S]methionine-labeled proteins indicated that E1 and C were unrelated to each other and to E2a and E2b, whereas the latter two gave similar, if not identical, maps. E1, E2a, and E2b were associated with the envelope and were located externally on the virus particle, whereas the C protein was associated with the RNA in the nucleocapsid. Solubilization of the virus with Triton X-100, followed by removal of the nucleocapsid and the detergent, resulted in the formation of soluble envelope protein complexes (rosettes) containing E1, E2a, and E2b. Although external labeling with [3H]borohydride and metabolic labeling with [3H]glucosamine suggested that all three proteins were glycosylated, only E1 and E2b were efficiently labeled with [3H]mannose. It is thus possible that the difference in migration between E2a and E2b is due to differences in glycosylation. Analysis by immunoprecipitation and sodium dodecyl sulfate-gel electrophoresis of intracellular [35S]methionine-labeled structural proteins synthesized in the presence and absence of tunicamycin supported the conclusion that E1 and E2 are glycoproteins. Unglycosylated E1 and E2 had an Mr of about 53,000 and 30,000, respectively.     

Relationships of the Col plasmids E2, E3, E4, E5, E6, and E7: Restriction mapping and colicin gene fusions

Thirteen ColE plasmids representing the E2-E7 types have been compared by restriction mapping. Over 80% of their restriction sites were found to be similarly positioned, indicating that these plasmids share a common structure. Three variants are ColE2-CA42 and ColE7-K317, both of which contain 1.8-kb DNA segments in place of a 2.5-kb segment common to the other plasmids, and ColE6-CT14, which has an additional 5.0-kb DNA segment compared to the other plasmids. The colicin (col), immunity (imm), and colicin release (hic) genes of these plasmids have been localized to regions corresponding to those known for ColE3-CA38 and ColE2-P9, with the imm and hic genes adjacent to the 3' end of the col gene. Active colicin is produced from hybrid col genes containing 5' and 3' ends from different E-type plasmids. The 3'-termini of the fused col genes specify the colicin type.     

Viral-mediated noisy gene expression reveals biphasic E2f1 response to MYC

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Highlights? Gene expression noise is an efficient means to probe dose responses ? Variability in MYC reveals biphasic E2f1 dose response ? Modeling predicts serum attenuates E2F repression by MYC ? Biphasic expression underlies discrimination of aberrant levels of growth signaling     

Mode of Action of Colicins of Types E1, E2, E3, and K

The effect of colicins on deoxyribonucleic acid and protein synthesis, and also their effect on the ability of T4 phage to replicate in Escherichia coli K-12, were studied. Colicins of type K inhibited deoxyribonucleic acid synthesis, protein synthesis, and phage growth. Among colicins of type E, there was an absolute correlation between mode of action and subdivision into types E(1), E(2), and E(3).     

Synthesis of (S)-13-Hydroxy (2E,4E,8E)- and (2E,4E,8Z)-Tetradecatrienoic Acids

The syntheses of (S)-13-hydroxy-(2E,4E,8E)-tetradecatrienoic acid (1) and (2E,4E,8Z)-tetradecatrienoic acid (2) were carried out by using the Wittig reaction as the key step. The asymmetric center at C-13 and the double bond between C-8 and C-9 for natural compound 1 were reconfirmed as being of (S) configuration and E, respectively.

The relationship between the structure of the unsaturated hydroxy fatty acids and their inhibitory effect on the growth of lettuce was investigated.