NMR detection of structures in the HIV-1 5'-leader RNA that regulate genome packaging

The 5'-leader of the HIV-1 genome regulates multiple functions during viral replication via mechanisms that have yet to be established. We developed a nuclear magnetic resonance approach that enabled direct detection of structural elements within the intact leader (712-nucleotide dimer) that are critical for genome packaging. Residues spanning the gag start codon (AUG) form a hairpin in the monomeric leader and base pair with residues of the unique-5' region (U5) in the dimer. U5:AUG formation promotes dimerization by displacing and exposing a dimer-promoting hairpin and enhances binding by the nucleocapsid (NC) protein, which is the cognate domain of the viral Gag polyprotein that directs packaging. Our findings support a packaging mechanism in which translation, dimerization, NC binding, and packaging are regulated by a common RNA structural switch.     

Photoexcited CRY2 interacts with CIB1 to regulate transcription and floral initiation in Arabidopsis

Cryptochromes (CRY) are photolyase-like blue-light receptors that mediate light responses in plants and animals. How plant cryptochromes act in response to blue light is not well understood. We report here the identification and characterization of the Arabidopsis CIB1 (cryptochrome-interacting basic-helix-loop-helix) protein. CIB1 interacts with CRY2 (cryptochrome 2) in a blue light-specific manner in yeast and Arabidopsis cells, and it acts together with additional CIB1-related proteins to promote CRY2-dependent floral initiation. CIB1 binds to G box (CACGTG) in vitro with a higher affinity than its interaction with other E-box elements (CANNTG). However, CIB1 stimulates FT messenger RNA expression, and it interacts with chromatin DNA of the FT gene that possesses various E-box elements except G box. We propose that the blue light-dependent interaction of cryptochrome(s) with CIB1 and CIB1-related proteins represents an early photoreceptor signaling mechanism in plants.     

Polo-like kinase Cdc5 controls the local activation of Rho1 to promote cytokinesis

The links between the cell cycle machinery and the cytoskeletal proteins controlling cytokinesis are poorly understood. The small guanine nucleotide triphosphate (GTP)-binding protein RhoA stimulates type II myosin contractility and formin-dependent assembly of the cytokinetic actin contractile ring. We found that budding yeast Polo-like kinase Cdc5 controls the targeting and activation of Rho1 (RhoA) at the division site via Rho1 guanine nucleotide exchange factors. This role of Cdc5 (Polo-like kinase) in regulating Rho1 is likely to be relevant to cytokinesis and asymmetric cell division in other organisms.     

Two new IncRNAs regulate the key immune factor NOD1 and TRAF5 in chicken lymphocyte

Reticuloendotheliosis virus (REV) causes the atrophy of immune organs and immuno-suppression in chickens, but the underlying molecular mechanism of the immune response after infection by REV is not well understood. Presently, the RNA-seq was used to analyze the regulation of immune response to REV in chicken lymphocytes from peripheral blood. Overall, 134 differentially expressed long non-coding RNAs (lncRNAs) between cells with REV infection or without in vitro were screened. Based on the differentially expressed protein-coding genes, the nucleotide-binding oligomerization domain (NOD)-like receptor pathway related to immune regulation was enriched. Two lncRNAs (L11530 and L09863) were predicted to target the NOD1 and tumor necrosis factor receptor-associated factor 5 (TRAF5) gene, respectively, which are involved in the NOD-like receptor pathway with cis-regulation way. The in vitro results revealed the significantly up-regulated (P<0.01) levels of lncRNA-L11530 and its target gene, NOD1, and the significantly down-regulated (P<0.05) levels of lncRNA-L09863 and its target gene, TRAF5, in lymphocytes after REV infection. These changes also occurred in vivo in blood lymphocytes of chickens infected with REV. Further, L09863 and L11530 were respectively interfered, the expression levels of their target genes NOD1 or TRAF5 were significantly down-regulated, accompanied by the change of IL-8 and IL-18 secretions in lymphocytes. The NOD-like receptor pathway appears to be important in the immune response to REV, LncRNA-11530 and IncRNA-09863 might involve in the immune regulation on REV infection by targeting NOD1 or TRAF5 in blood lymphocytes of chickens. Our findings reveal a new regulation of lncRNAs (L11530 and L09863) on immunity in chicken peripheral blood lymphocytes for REV infection by changing the expression of the target genes via the NOD-like receptor pathway.     

OsDXR interacts with OsMORF1 to regulate chloroplast development and the RNA editing of chloroplast genes in rice

Plant chlorophyll biosynthesis and chloroplast development are two complex processes that are regulated by exogenous and endogenous factors. In this study, we identified OsDXR, a gene encoding a reductoisomerase that positively regulates chlorophyll biosynthesis and chloroplast development in rice. OsDXR knock-out lines displayed the albino phenotype and could not complete the whole life cycle process. OsDXR was highly expressed in rice leaves, and subcellular localization indicated that OsDXR i...     

Biologic features of HIV-1 that correlate with virulence in the host

Individuals infected with the human immunodeficiency virus type 1 (HIV-1) may be asymptomatic or have AIDS-related complex or the acquired immuno deficiency syndrome (AIDS). Little is known about the factors that influence progression of infection to AIDS. In this study of isolates of HIV-1 obtained at intervals during the infection of four individuals, the development of disease was found to be correlated with the emergence of HIV-1 variants that were more cytopathic in vitro as the disease progressed and that replicated more efficiently in a wide variety of different human cells. The biologic properties of HIV-1 in vitro thus appear to reflect its virulence in the host. Further studies of such sequentially isolated viruses may lead to the identification of viral genes that govern pathogenesis.     

Factors that contribute to the mycoparasitism stimulus in Trichoderma atroviride strain P1

Trichoderma atroviride strain P1 has been used extensively to study the mycoparasitic mechanisms in the interaction between plant pathogenic host and beneficial antagonistic fungi. Mutants of P1 containing the green fluorescent protein (gfp) or glucose oxidase (gox) reporter systems and different inducible promoters (from the exochitinase nag1 gene, or the endochitinase ech42 gene of P1) were used to determine the factors that activate the biocontrol gene expression cascade in the antagonis…     

Coupling of stress in the ER to activation of JNK protein kinases by transmembrane protein kinase IRE1

Malfolded proteins in the endoplasmic reticulum (ER) induce cellular stress and activate c-Jun amino-terminal kinases (JNKs or SAPKs). Mammalian homologs of yeast IRE1, which activate chaperone genes in response to ER stress, also activated JNK, and IRE1alpha-/- fibroblasts were impaired in JNK activation by ER stress. The cytoplasmic part of IRE1 bound TRAF2, an adaptor protein that couples plasma membrane receptors to JNK activation. Dominant-negative TRAF2 inhibited activation of JNK by IRE1. Activation of JNK by endogenous signals initiated in the ER proceeds by a pathway similar to that initiated by cell surface receptors in response to extracellular signals.     

不同H_5亚型禽流感灭活苗对鸡H_5N_1株的免疫效力试验

采用H5N2和H5N1两种类型的禽流感(A I)油乳灭活疫苗免疫鸡群对高致病性A I流行株H5N1A IV的攻毒保护效力进行了比较。结果表明:在同等免疫剂量条件下,H5N2和H5N1油乳灭活苗对鸡群具有相似或同等的免疫效力,均能抵抗对高致病性A IH5N1流行株的攻击;A I母源抗体对灭活苗免疫具有一定的干扰作用。     

不同H5亚型禽流感灭活苗对鸡H5N1株的免疫效力试验

采用H5N2和H5N1两种类型的禽流感（AI）油乳灭活疫苗免疫鸡群对高致病性AI流行株H5N1AIV的攻毒保护效力进行了比较。结果表明：在同等免疫剂量条件下，H5N2和H5N3油乳灭活苗对鸡群具有相似或同等的免疫效力，均能抵抗对高致病性AIH5N1流行株的攻击；AI母源抗体对灭活苗免疫具有一定的干扰作用。     

核桃早实性相关SCAR标记(1-1500)基因末端序列的克隆

[目的]克隆SCAR标记的核桃早实性相关基因片段[1](AFLP早实分子标记转化成的SCAR标记)的末端序列,为验证其功能和早实核桃分子育种奠定基础.[方法]采用RACE技术对SCARE标记的核桃早实性相关基因片段设计特异性PCR引物,并扩增其末端序列.[结果]分别获得了长度为453 bp和463 bp的片段,通过与NCBI核酸数据库中已经发表的序列进行比对分析,发现该基因3'末端含有358个核苷酸非编码序列.其核酸序列与葡萄假定蛋白相应部位同源性为55.26;,与葡萄重叠群相应部位同源性为38.38;,与线虫枯粒Y38F2AR基因全序列相应部位相似性为40.86;,和野猪免疫球蛋白超家族成员相应部位的相似性为39.75;,具有poly(A)尾.5'末端含有248个核苷酸非编码序列,其核酸序列与葡萄重叠群基因组鸟枪全序列相应部位同源性为39.07;,与拟南芥基因组DNA 3号染色体相应部位的同源性为42.22;,与嗜热四膜虫假定蛋白基因序列相应部位相似性为44.53;,和斑马鱼DNA序列DKEY-120E17克隆2号连锁群全序列相应部位相似性为42.30;.[结论]试验采用的3'和5'末端快速扩增技术(3'RACE和5'RACE技术)能很好地扩增核桃早实性相关基因的末端序列.     

病虫双抗杂交棉新组合F1代试验

介绍了病虫双抗杂交棉9个新组合F1代比较试验和结果.     

Rapid progression to AIDS in HIV+ individuals with a structural variant of the chemokine receptor CX3CR1

Human immunodeficiency virus (HIV) enters cells in vitro via CD4 and a coreceptor. Which of 15 known coreceptors are important in vivo is poorly defined but may be inferred from disease-modifying mutations, as for CCR5. Here two single nucleotide polymorphisms are described in Caucasians in CX3CR1, an HIV coreceptor and leukocyte chemotactic/adhesion receptor for the chemokine fractalkine. HIV-infected patients homozygous for CX3CR1-I249 M280, a variant haplotype affecting two amino acids (isoleucine-249 and methionine-280), progressed to AIDS more rapidly than those with other haplotypes. Functional CX3CR1 analysis showed that fractalkine binding is reduced among patients homozygous for this particular haplotype. Thus, CX3CR1-I249 M280 is a recessive genetic risk factor in HIV/AIDS.     

Evolutionary Patterns of the Proviral gp90 V3 to V5 Regions of Equine Infectious Anemia Virus Associated with Immune Selection in Progressors and Nonprogressors

The aim of this study was to determine the genomic evolutionary pattern of virulent equine infectious anemia virus (EIAV)during persistent infection.The evolutionary dynamics of proviral genomes were examined by challenging an EIAV seronegative equine (pony 1) and three EIAV vaccinated equines (ponies 4,7,and 8) with the Chinese virulent strain EIAVL.Ponies I and 7 succumbed to disease and were called progressors,while ponies 4 and 8 lacked clinical symptoms and were considered nonprogressors.Sequences spanning the V3,V4,and V5 hyper-variable regions of the EIAV-L envelope gp90 gene were sequenced from each pony as evolutionary markers of the provirus.The proviral genome of the EIAV-Linoculum evolved during persistent infection and displayed different patterns between EIA progressors and nonprogressors.Inoculum-like variants were isolated from nonprogressors during persistent infection,but only from progressors during acute infection.Variant mutations from nonprogressors were dispersed throughout the sequenced region,while those from progressors were predominantly localized to V3.Humoral immunity and virus variant population selection analyses indicated that immune selection was positive in chronically infected progressors and weak in nonprogressors.In-frame stop codons were frequently localized to a defect "hot spot".The high number of defective variants in nonprogressors may promote disease survival.