Human leukocyte and fibroblast interferons are structurally related

The coding sequences of the dDNAs of cloned human leukocyte interferon I and human fibroblast interferon show homologies of 45% at the nucleotide and 29% at the amino acid level. We conclude that the two genes were derived from a common ancestor.     

A unique set of polypeptides is induced by gamma interferon in addition to those induced in common with alpha and beta interferons

Human immune interferon (IFN-gamma) differs from leukocyte interferon (IFN-alpha) and fibroblast interferon (IFN-beta) in cell origin, inducing agents, physical and biological properties and amino acid sequence. These differences have led to interest in possible differences in the biological properties of IFN-gamma compared with IFN-alpha and IFN-beta. IFN-gamma has the same broad range of biochemical and biological actions as do IFN-alpha and IFN-beta, although relative potencies vary depending on the cell type and function investigated. There has so far been no direct evidence that IFN-gamma alters normal cell functions differently from other interferons. We report here striking qualitative and quantitative differences in the intracellular response of human fibroblasts to IFN-gamma compared with IFN-alpha and IFN-beta. Two-dimensional gel electrophoresis demonstrates, in addition to the induction of a common group of polypeptides, the existence of a set of polypeptides whose synthesis is uniquely induced by IFN-gamma.     

Complete nucleotide sequence of an influenza virus haemagglutinin gene from cloned DNA

A synthetic fowl plague virus (FPV) haemagglutinin gene has been cloned in bacteria and the complete sequence of the RNA gene deduced. It is 1,742 nucleotides long and the mRNA codes for 56.3 amino acids in an uninterrupted sequence. The nature of some of the important domains in the haemagglutinin has been established, and their structure is discussed in relation to their function. Extensive amino acid sequence homologies exist between FPV and human influenza haemagglutinins.     

家猪BMP-2、BMP-3基因克隆及其组织表达探究

本研究以长白猪(Landrace)肺cDNA为模板,扩增获得猪骨形态发生蛋白BMP-2和BMP-3基因的cDNA全长.BMP-2基因cDNA全长为1742bp,编码395个氨基酸的前体蛋白,与人、牛、绵羊、大鼠、小鼠等的BMP-2基因的氨基酸序列一致性分别94.18%,95.4%,95.2%,90.3%,90.60%;BMP-3基因cDNA全长为1639bp,编码475个氨基酸的前体蛋白,猪与人、牛、绵羊、大鼠、小鼠等的BMP-3氨基酸序列的一致性分别是84.7%、87.7%、82.3%、80.4%、79.5%.采用RT-PCR方法,对BMP-2、3基因在家猪主要组织的表达进行探究.结果显示:BMP-2在所有组织中均有表达;而BMP-3在脑、肺、小肠中表达量较高,其他组织中表达量弱.     

蛋白质二级结构由氨基酸和mRNA序列编码

据氨基酸序列,密码子序列和蛋白质二级结构序列的比较,指出约18％的两肽的密切子具有反常的蛋白质结构偏好性,并且这种以常不能用随机涨落解释,因而关于蛋白质折迭的Anfinsen原理可能需要作适当修正。     

猪Akt1、Akt2基因克隆与组织表达图谱分析

为了得到长白猪蛋白激酶Akt1和Akt2基因序列并分析其表达模式,本研究使用RT-PCR方法,首先克隆了蛋白激酶Akt1和Akt2的cDNA.序列分析显示:长白猪Akt1基因的cDNA全长1461bp,编码具480个氨基酸残基的前体蛋白,其氨基酸序列与人,牛,大鼠,小鼠同源性达到97%以上.长白猪Akt2基因cDNA全长为1505bp,编码具481个氨基酸残基的前体蛋白,其氨基酸序列与人,牛,大鼠,小鼠的同源性高达97%以上.SMART分析表明,猪Akt1和Akt2蛋白均包含了与PI-3K结合的PH结构域及2个具有丝氨酸/苏氨酸激酶催化活性的S_TKc结构域.RT-PCR检测结果显示:Akt1mRNA在垂体、心脏、肝脏、脾脏、肌肉组织中高表达,在大脑、小脑、肾脏表达丰度较低.Akt2则在小脑、垂体、心脏、肝脏、脾脏和肌肉组织中高表达,而在大脑和肾脏中表达丰度较低.     

Human preprovasoactive intestinal polypeptide contains a novel PHI-27-like peptide, PHM-27

Vasoactive intestinal polypeptide (VIP), a 28-amino acid peptide originally isolated from porcine duodenum, is present not only in gastrointestinal tissues but also in neural tissues, possibly as a neurotransmitter, and exhibits a wide range of biological actions (for example, relaxation of smooth muscle, stimulation of intestinal water and electrolyte secretion and release of insulin, glucagon and several anterior pituitary hormones). As the structure of porcine and bovine VIP shows several similarities to those of mammalian glucagon, secretin and gastric inhibitory peptide (GIP), VIP is considered to be a member of the glucagon-secretin family. Recently, we have found that VIP is synthesized from a precursor, pro-VIP (molecular weight (Mr) 17,500), in human neuroblastoma cells and that the primary translation product of the mRNA encoding VIP is prepro-VIP (Mr 20,000). In an attempt to elucidate the primary structure of the precursor, we have now cloned the DNA sequence complementary to the mRNA coding for human VIP and analysed the nucleotide sequence. The entire amino acid sequence of the precursor, deduced from the nucleotide sequence, indicates that the precursor protein contains not only VIP but also a novel peptide of 27 amino acids. The peptide, designated PHM-27, differs by only 2 amino acids from PHI-27, a peptide recently isolated from porcine intestine, and is also closely related in sequence to VIP.     

小熊猫脑源性神经营养因子（BDNF）基因的克隆与序列分析

参照人的ＢＤＮＦ基因序列设计了一对引物，利用聚合酶链式反应（ＰＣＲ），从小熊猫基因组ＤＮＡ中扩增和克隆到ＢＤＮＦ基因。序列分析表明，小熊猫和人的ＢＤＮＦ基因核苷酸序列同源性为９３％，而与大熊猫ＢＤＮＦ基因的核苷酸序列同源性高达９８％。在推导的多肽序列中，除在前导肽区有两个氨基酸的差异外，小熊猫ＢＤＮＦ的成熟区与人和其他报道的哺乳动物ＢＤＮＦ成熟区的氨基酸序列完全一致，显示了极高的保守性。     

Human epidermal growth factor receptor cDNA sequence and aberrant expression of the amplified gene in A431 epidermoid carcinoma cells

The complete 1,210-amino acid sequence of the human epidermal growth factor (EGF) receptor precursor, deduced from cDNA clones derived from placental and A431 carcinoma cells, reveals close similarity between the entire predicted v-erb-B mRNA oncogene product and the receptor transmembrane and cytoplasmic domains. A single transmembrane region of 23 amino acids separates the extracellular EGF binding and cytoplasmic domains. The receptor gene is amplified and apparently rearranged in A431 cells, generating a truncated 2.8-kilobase mRNA which encodes only the extracellular EGF binding domain.     

Cloning and sequence analysis of cDNA encoding a precursor for human atrial natriuretic polypeptide

Recent identification of natriuretic-diuretic activity in peptides isolated from human and rat atrial tissue implicates them in the control of extracellular fluid volume and electrolytic homeostasis. The presence of multiple forms of the peptides ranging from 3,000 to 13,000 molecular weight (MW) suggests they may all derive from the same precursor. The established amino acid sequence of alpha-human atrial natriuretic polypeptide (alpha- hANP ), a 28-residue peptide with potent natriuretic activity, provided the means to elucidate the structure of the precursor for alpha- hANP and the gene encoding it. Here we report the cloning and sequence analysis of the cDNA of human atrial mRNA encoding a precursor of alpha- hANP . The cDNA encodes gamma-human atrial natriuretic polypeptide (gamma- hANP ) of 13,000 MW, whose C-terminal 28 amino acid residues may be processed as alpha- hANP .     

Structure of rat atrial natriuretic factor precursor deduced from cDNA sequence

The atrium of the heart contains peptides, termed atrial natriuretic factors ( ANFs ), diuretic and smooth-muscle-relaxing activities. In view of its potent effects on salt metabolism in the kidney and on vascular smooth muscle, ANF is considered to play an important part in the control of fluid volume and vascular function. Several different ANF peptides varying in size have been isolated and their amino acid sequences determined. Analysis of the sequences of the peptides suggests that they are derived by proteolysis from the same precursor. To examine this hypothesis, we have cloned cDNAs of the ANF precursor using rat atrial mRNA, determined its nucleotide sequence and deduced its amino acid sequence. The ANF precursor consists of 152 amino acid residues including a putative signal peptide sequence. This sequence contains the amino acid sequences of all the ANF peptides reported to date.     

猪STAT4、STAT6基因克隆及组织表达研究

本研究以长白猪为材料,克隆了STAT4和STAT6基因的cDNA全长,其中STAT4基因cDNA全长2269 bp,编码748个氨基酸的前体蛋白,与人、牛、大鼠、小鼠等哺乳动物STAT4氨基酸序列一致性分别为97%、98%、96%、96%;STAT6基因cDNA全长2637 bp,编码847个氨基酸的前体蛋白,与人、牛、大鼠、小鼠等哺乳动物的氨基酸序列有很高的同源性,分别为93%、95%、88%和87%.采用RT-PCR方法,本研究对家猪STAT4和STAT6基因进行组织表达分析.结果显示:STAT4在所有组织中都有表达,STAT6在心、肝、脾、肺、肾、肌肉、小肠等组织中有表达.此外,本研究已将家猪STAT4和STAT6基因编码区序列克隆到真核表达栽体pcDNA3.1(+)中,并做了初步功能鉴定.     

mRNA序列与蛋白序列对比

生物序列的对比是计算生物学中的一个基本问题．目前已有许多算法对DNA序列或蛋白序列之间进行对比,多是对同种生物序列进行对比．为得到mRNA序列和蛋白序列之间的对比,采用动态规划算法,提供了寻求mRNA序列和蛋白序列的局部对比和全局对比,解决了核酸与氨基酸之间的对比问题．算法的时间复杂度为O(nm)．     

Expression of human fibroblast interferon gene in Escherichia coli

The human fibroblast interferon gene was inserted in a thermoinducible expression plasmid under control of the phage lambda PL promoter. The primary translation products predicted on the basis of the plasmid constructions were hybrid proteins starting with beta-lactamase or phage MS2 polymerase information followed by the total preinterferon. On induction, antiviral activity, whose physico-chemical, immunological and biological characteristics closely corresponded to those of authentic human fibroblast interferon, was synthesized. Processing to a size compatible with mature but unglycosylated authentic product was observed.     

山羊FGF5基因cDNA分子克隆及序列分析

采用逆转录-聚合酶链式反应(RT-PCR)技术,首次从山羊脑组织总RNA中扩增出成纤维细胞生长因子5(FGF 5)基因的cDNA编码序列.通过对序列的分析表明,克隆的山羊FGF 5cDNA编码序列与其他动物的序列具有高度的同源性.与G enbank中人和小鼠序列比较,山羊与人和小鼠的FGF 5核苷酸序列的同源性分别为91%和87%.编码的氨基酸序列比较,山羊和人的相似性为87%,山羊与小鼠的相似性为83%.如FGF s家族的其他成员一样,山羊的FGF 5蛋白也有一信号肽序列.山羊FGF 5基因外显子在编码氨基酸时,对同义密码子的使用表现有强烈的偏好性.不同物种对同义密码子使用的偏倚程度与偏好类型各不相同,也具有种属特异性.山羊FGF 5基因所编码的蛋白质中,20种氨基酸的含量差异很大,极性氨基酸含量高于非极性氨基酸含量.     

Cloning and identification of a novel human glioma differentiation related gene GDR1

In order to identify the genes associated with glioblastoma differentiation, some ESTs, expressed differentially in the control cell and the differentiated human glioblastoma cell line BT-325 induced by the all-trans retinoid acid, have been isolated by the method of DDRT-PCR. Of the 46 ESTs sequenced, 19 are from new genes. A full-length 1 535-bp cDNA, termed gene GDR1, has been isolated from the human cDNA library using the probe designed according to one of the novel ESTs, HGBB098. The open reading frame of GDR1 gene encodes a putative protein containing 334 amino acid residues. Blast against the current GenBank DNA and protein sequence database did not reveal significant homology with any known proteins. RT-PCR shows that GDR1 mRNA level increased in the differentiated BT-325 cells after being treated with RA. The different expression patterns of GDR1 mRNA in human tissues have been detected through the multiple tissue Northern blot hybridization.     

Structure and expression of a cloned cDNA for human interleukin-2

A cDNA coding for human interleukin-2 (IL-2) has been cloned from a cDNA library prepared from partially purified IL-2 mRNA. The DNA sequence codes for a polypeptide which consists of 153 amino acids including a putative signal sequence. A biologically active polypeptide, characteristic of human IL-2, was produced when the cDNA was fused to a simian virus 40 promoter sequence and used to transfect cultured monkey COS cells.     

人Rab蛋白cDNA的克隆和表达

从人胎脑cDNA文库中克隆到一种新的Rab cDNA,全长920bp,以编码213个氨基酸残基,该蛋白预测的分子质量为24567u,等电点7．34,经同源比较,该cDNA与GenBank数据库中登录号为X14964的Rab蛋白有83％的相似性和76％的相同性,将该cDNA克隆到经改造的PBV220表达质粒,转化DH5a菌株诱导表达出该蛋白,取24种不同组织的总cDNA各100ng,用该基因序列设计引物作PCR,结果在胎肝组织中检测到有明显条带,表明该Rab基因相对在胎肝有高表达。