Transformation and plasmacytoid differentiation of EBV-infected human B lymphoblasts by ras oncogenes

The biological effects of ras oncogene activation in B cells were studied by using amphotropic retroviral vectors to introduce H- or N-ras oncogenes into human B lymphoblasts immortalized by Epstein-Barr virus. Expression of both H- and N-ras oncogenes led to malignant transformation of these cells, as shown by clonogenicity in semisolid media and tumorigenicity in immunodeficient mice. In addition, terminal differentiation into plasma cells was detectable as specific changes in morphology, immunoglobulin secretion, and cell surface antigen expression. This combined effect, promoting growth and differentiation in human lymphoblasts, represents a novel biological action of ras oncogenes and has implications for the pathogenesis of terminally differentiated B-lymphoid malignancies such as multiple myeloma.     

Primary rat embryo cells transformed by one or two oncogenes show different metastatic potentials

Second-passage rat embryo cells were transfected with a neomycin resistance gene and the activated form of the c-Ha-ras I gene, or with these two genes plus the adenovirus type 2 E1a gene. Foci of morphologically transformed cells were observed in both cases; however, the frequency of transformation was at least ten times higher with two oncogenes than with the ras gene alone. All the transformed cell lines gave rise to rapidly growing tumors when injected subcutaneously into nude mice. All but one of the cell lines transformed by the ras oncogene alone formed metastatic nodules in the lungs of animals that had been injected subcutaneously with transformed cells. When transformed cells were injected intravenously, all the ras single-gene transformants gave rise to many metastatic lung nodules. In contrast, cell lines transformed with ras and E1a did not generate metastases after subcutaneous injection and gave rise to very few metastatic lung nodules after intravenous injection. These data demonstrate that a fully malignant cell with metastatic potential, as measured in an immunodeficient animal, can be obtained from early passage embryo cells by the transfection of the ras oncogene alone.     

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.     

钙依赖蛋白激酶与植物钙离子的信号转导

钙离子所依赖的蛋白激酶(CDPKs)在植物钙信号转导过程中发挥着关键作用。本文就CDPK的结构以及生物学功能等方面做了较为详尽的阐述。     

Periodic signaling controlled by an oscillatory circuit that includes protein kinases ERK2 and PKA

Self-regulating systems often use robust oscillatory circuits. One such system controls the chemotactic signaling mechanism of Dictyostelium, where pulses of adenosine 3',5'-monophosphate (cAMP) are generated with a periodicity of 7 minutes. We have observed spontaneous oscillations in activation of the mitogen-activated protein (MAP) kinase ERK2 that occur in phase with peaks of cAMP, and we show that ERK2 modulates cAMP levels through the phosphodiesterase RegA. Computer modeling and simulations of the underlying circuit faithfully account for the ability of the cells to spontaneously generate periodic pulses during specific stages of development. Similar oscillatory processes may occur in cells of many different species.     

绿色荧光蛋白基因标记芒果畸形病病原菌研究

芒果畸形病是世界性的芒果重要病害。采用PEG介导的原生质体转化法用绿色荧光蛋白(GFP)表达载体(pCT74-sGFP)转化芒果畸形病病原菌(Fusarium proliferatum),获得了表达GFP的转化子。转化子经过单孢纯化后连续继代培养仍能发出稳定而强烈的荧光,通过GFP特异性引物PCR扩增转化子基因组获得预期片段,表明GFP基因已成功转入芒果畸形病病原菌基因组中且稳定遗传。GFP标记菌株生长正常,致病性和野生菌丝无差别。获得GFP标记的转化子,为应用发绿色荧光的芒果畸形病病原菌研究病原菌的侵染方式、扩展过程等奠定了基础。     

The control of the metabolic switch in cancers by oncogenes and tumor suppressor genes

Cells from some tumors use an altered metabolic pattern compared with that of normal differentiated adult cells in the body. Tumor cells take up much more glucose and mainly process it through aerobic glycolysis, producing large quantities of secreted lactate with a lower use of oxidative phosphorylation that would generate more adenosine triphosphate (ATP), water, and carbon dioxide. This is the Warburg effect, which provides substrates for cell growth and division and free energy (ATP) from enhanced glucose use. This metabolic switch places the emphasis on producing intermediates for cell growth and division, and it is regulated by both oncogenes and tumor suppressor genes in a number of key cancer-producing pathways. Blocking these metabolic pathways or restoring these altered pathways could lead to a new approach in cancer treatments.     

Human cytomegalovirus directly induces the antiviral protein viperin to enhance infectivity

Viperin is an interferon-inducible protein that is directly induced in cells by human cytomegalovirus (HCMV) infection. Why HCMV would induce viperin, which has antiviral activity, is unknown. We show that HCMV-induced viperin disrupts cellular metabolism to enhance the infectious process. Viperin interaction with the viral protein vMIA resulted in viperin relocalization from the endoplasmic reticulum to the mitochondria. There, viperin interacted with the mitochondrial trifunctional protein that mediates β-oxidation of fatty acids to generate adenosine triphosphate (ATP). This interaction with viperin, but not with a mutant lacking the viperin iron-sulfur cluster-binding motif, reduced cellular ATP generation, which resulted in actin cytoskeleton disruption and enhancement of infection. This function of viperin, which was previously attributed to vMIA, suggests that HCMV has coopted viperin to facilitate the infectious process.     

Transgenic Crysanthemum plants transformed with the gene encoding for the virus B coat protein

Chrysanthemum transgenic plants with integrated single and double copies of the gene encoding for the virus B coat protein have been created via Agrobacterium-mediated transformation. Both mRNA and the gene product have been revealed in several transformed lines only. The use of the transgenic chrysanthemum plants in the development of varieties resistant to the B virus is discussed.     

Nucleotide sequence of the oncogene encoding the p21 transforming protein of Kirsten murine sarcoma virus

The transforming protein ofKirsten murine sarcoma virus (Ki-MuSV) is a virally encoded 21-kilodalton protein called p21 kis. The sequences encoding p21 kis were genetically localized to a 1.3-kilobase segment near the 5' end of the viral genome by assaying the capacity of a series of defined deletion mutants of molecularly cloned Ki-MuSV DNA to induce focal transformation of mouse cells. Nucleotide sequencing of a portion of this region has led to the identification of an open reading frame of 567 nucleotides coding for p21 kis protein.     

Nucleotide sequence of a bovine clone encoding the angiogenic protein, basic fibroblast growth factor

Basic and acidic fibroblast growth factors (FGF's) are potent mitogens for capillary endothelial cells in vitro, stimulate angiogenesis in vivo, and may participate in tissue repair. An oligonucleotide probe for bovine basic FGF was designed from the nucleotide sequence of the amino-terminal exon of bovine acidic FGF, taking into account the 55 percent amino acid sequence homology between the two factors. With this oligonucleotide probe, a full length complementary DNA for basic FGF was isolated from bovine pituitary. Basic FGF in bovine hypothalamus was shown to be encoded by a single 5.0-kilobase messenger RNA; in a human hepatoma cell line, both 4.6- and 2.2-kilobase basic FGF messenger RNA's were present. Both growth factors seem to be synthesized with short amino-terminal extensions that are not found on the isolated forms for which the amino acid sequences have been determined. Neither basic nor acidic FGF has a classic signal peptide.     

农杆菌介导转化甜菜影响因素的研究

[目的]以甜菜无菌苗的叶柄为外植体材料,对农杆菌转化条件和方法进行较为系统地比较研究,以期建立一种转化频率高、稳定性好、通用性较强的甜菜遗传转化技术体系.[方法]对影响农杆菌介导的不同因素分别进行比较试验.[结果]对甜菜叶柄进行培养后用不同菌液浓度OD600=0.3～0.4的农杆菌感染8～10 min,脱菌处理后接入卡那霉素浓度为100 mg/L、头孢霉素浓度为500 mg/L的选择培养基中进行筛选,获得的抗性芽较多,抗性芽分化频率可达到34.3;.[结论]初步建立了一种转化频率高、稳定性好、通用性较强的甜菜遗传转化技术体系,通过植物转基因技术为选育高产、优质、广谱抗病的甜菜品种奠定基础.     

Human CSF-1: molecular cloning and expression of 4-kb cDNA encoding the human urinary protein

A 4-kilobase complementary DNA (cDNA) encoding human macrophage-specific colony-stimulating factor (CSF-1) was isolated. When introduced into mammalian cells, this cDNA directs the expression of CSF-1 that is structurally and functionally indistinguishable from the natural human urinary CSF-1. Direct structural analysis of both the recombinant CSF-1 and the purified human urinary protein revealed that these species contain a sequence of at least 40 amino acids at their carboxyl termini which are not found in the coding region of a 1.6-kilobase CSF-1 cDNA that was previously described. These results demonstrate that the human CSF-1 gene can be expressed to yield at least two different messenger RNA species that encode distinct but related forms of CSF-1.     

含MDV gB CTL表位与鸡HSP108融和蛋白基因的构建及原核表达

【目的】为新型马立克氏病(MD)疫苗的开发奠定基础。【方法】以SPF鸡肝脏中提取RNA为模板,利用RT-PCR反应扩增鸡HSP108基因;利用PCR方法扩增MDV gB CTL表位基因,并将MDV gB CTL表位基因与鸡HSP108融合在一起,构建融合蛋白基因rgBHSP108,将该融合蛋白基因克隆入原核表达载体pET-28a中,构建重组表达载体pET-gBHSP108,将该重组载体转化E.coliBL21(DE3),并用IPTG诱导融合蛋白rgBHSP108的表达,对rgBHSP108进行SDS-PAGE电泳、可溶性分析、蛋白纯化及Western-blot分析。【结果】扩增到鸡2.4kb的HSP108基因和330bp的MDV gB CTL表位基因;克隆的鸡HSP108基因序列与GenBank上发表的鸡输卵管HSP108(NM204289)和来源于肝脏HSP108(AF387865)核苷酸的同源性分别为99.7%和99.0%。rgBHSP108融合蛋白基因构建成功;融合蛋白rgBHSP108以包涵体的形式获得高效表达并纯化。Western-blot分析表明,针对MDV gB CTL表位的多抗可以与融合蛋白发生特异性反应。【结论】成功构建了鸡HSP108融合蛋白基因,利用原核表达系统成功表达rgBHSP108。     

农杆菌介导的甘蔗遗传转化研究

选用在组织培养过程中能够产生分泌较多酚类物质的甘蔗基因型福农８６／１７为材料．以幼叶切段为外植体，采用叶盘法与土壤根癌农杆菌菌珠ＬＢＡ４４０４（ｐＡＬ４４０４：：ＰＴＤ１）菌液并培养。外植体设预培养１天、３天、５天、７天和１０天五种时间，农杆菌设稀释１０倍和２０倍两种浓度，共１０种处理组合，共培养４８小时。结果预培养５天，农杆菌稀释１０倍和２０倍两种处理组合的外植体．在含卡那霉素３００ｍｇ／Ｌ的选择诱导和选择继代培养基中诱导并形成抗性愈伤组织。     

蛋用鹌鹑伴性羽色基因互作与连锁的关系

目的研究MITF基因在鹌鹑胚胎发育过程中的表达变化及其与羽色形成的关系,分析启动子甲基化对MITF基因表达的影响。方法利用RT-PCR克隆鹌鹑MITF基因mRNA的CDS区域并进行DNA测序,对得到的序列进行BLAST比对等生物信息学分析。利用RT-qPCR分析MITF基因在栗羽朝鲜鹌鹑和北京白羽鹌鹑胚胎发育第6、8、10、12和14 天的表达变化。克隆朝鲜鹌鹑和北京白羽鹌鹑MITF基因的启动子区域并进行DNA测序,利用BS-PCR分析启动子CpG岛的甲基化水平。结果鹌鹑MITF基因与日本鹌鹑同源基因相似度达99%,包含1 476 bp的开放阅读框,编码蛋白由492个氨基酸残基组成,没有信号肽和明显的跨膜区,成熟蛋白位于细胞核中。在胚胎发育的6~12 d,朝鲜鹌鹑MITF基因mRNA表达水平显著或极显著高于北京白羽鹌鹑(P<0.05或P<0.01)。鹌鹑MITF基因启动子区域包含丰富的顺式作用元件和1个346 bp的CpG岛,朝鲜鹌鹑MITF基因启动子区域的平均甲基化水平为18.52%,北京白羽鹌鹑的平均甲基化水平为29.63%,两者差异显著(P<0.05)。结论北京白羽鹌鹑MITF基因启动子区域高甲基化状态导致其表达水平下降,这与其羽色白化有一定的关系。     

Gene encoding the beta subunit of S100 protein is on chromosome 21: implications for Down syndrome

S100 protein is a calcium-binding protein found predominantly in the vertebrate nervous system. Genomic and complementary DNA probes were used in conjunction with a panel of rodent-human somatic cell hybrids to assign the gene for the beta subunit of S100 protein to the distal half of the long arm of human chromosome 21. This gene was identified as a candidate sequence which, when expressed in the trisomic state, may underlie the neurologic disturbances in Down syndrome.