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1.
DnaJ—like基因在不同环境胁迫下的表达研究   总被引:5,自引:0,他引:5  
PvSR6(Phaseolus vulgaris stress-related)基因编码一种菜豆DnaJ-like蛋白。North-ern blot结果表明:PvSR6基因在未处理的菜豆叶片中表达较少,重金属(Hg^2+和Cd^2+)、机械损伤、UV、高温和水杨酸等环境胁迫能强烈地促进其基因的转录,推测DnaJ-like蛋白在保护细胞膜和酶蛋白的结构和功能及提高植物的抗逆性方面有重要作用。  相似文献   

2.
柴团耀  张玉秀 《生命科学》1999,11(4):172-175
DnaJ-like蛋白由N-端保守的J区域、富含Gly和Phe区域,富含Gys区域和C-端低同源区域组成。J功能域能调节HSP70分子伴侣的ATPase活性,C-端不保守域能调节与多肽的关系。直核细胞中存在着多种结构不同的DnaJ-like蛋白,但都含有一个J功能域。DnaJ-like蛋白通过J功能域调节HSP70功能而参与蛋白的折叠,装配和运输过程。  相似文献   

3.
伪狂犬病毒蛋白激酶基因的PCR扩增及其克隆鉴定   总被引:9,自引:0,他引:9  
以BHK-21细胞单层上增殖的伪狂犬病毒(Pseudorabiesvirus,PRV),经离心浓缩后,用SDS-蛋白酶K消化法分离纯化PRV基因组DNA。参照PRVKa株和NIA-3株蛋白激酶(PK)基因的DNA序列,设计并合成了一对长度为26bp和32bp的引物,以纯化的PRV基因组DNA为模板,用PCR技术成功地扩增出我国伪狂犬病毒地方株的PK基因,并将它克隆于pUC19载体。酶切分析结果表明,所获PK基因克隆在PstI、SmaI、XhoI和SalI上的切点与PRVNIA-3株相同。为下一步进行PK基因的体外缺失和重组,以构建减毒的PK缺失疫苗株奠定了基础。  相似文献   

4.
禾本科植物的起源,进化及分布   总被引:6,自引:0,他引:6  
禾本科植物的起源、进化及分布韩建国樊奋成李枫(中国农业大学草地研究所,北京100094)ORIGIN,EVOLUTIONANDDISTRIBUTIONOFTHEGRAMINEAEHanJian-guoFanFen-chengLiFeng(Grassl...  相似文献   

5.
用pUC19质粒作载体,克隆了黄地老虎颗粒体病毒(Agrolissegetumgranulosisvirus,简称AsGV)DNAPstI-D.E.F.G.H.J.K.等7个片段。以[ ̄(32)P]-dCTP标记的油桐尺蠖核型多角体病毒(Buzurasuppressarianuclcarpolyhedrosisvirus简称BsNPV)多角体蛋白基因为探针,在37℃条件下对AsGV)颗粒体蛋白基因进行了定位,将其分别定位于BslⅡ-S或TPsTI-A或B和EciRI-A片段上。  相似文献   

6.
任冰  程玉林 《微生物与感染》1998,21(5):21-24,47
肠球菌对糖肽类耐药表分VanA,VanB和VanC3种,VanA型最常见,耐药质粒携带转座子Tn1546,Tn1546带有一系列耐药基因,它们的基因产物共同作用,导致菌株对糖肽类药物耐药。其中连接酶(VanA)和脱氢酶(VanH)催化合成D-Ala-D-Lac,替代D-Ala-D-Ala连接入肽聚糖前体,阻止了糖肽与细胞壁的结合,D,D-二肽酶(VanX)通过水解D-Ala-D-Ala而抑制正常肽  相似文献   

7.
为建立鸭乙型肝炎病毒LJ-76的转染细胞系,将LJ-76病毒DNA插入到pUC19的EcoRⅠ位点上,分离得到含有双拷贝LJ-76DNA的重组质粒.通过磷酸钙沉淀方法,将经CsCl等密度离心纯化的LJ-76DNA双体导入到人肝癌细胞BEL7402中.收集转染细胞的培养液进行蔗糖密度梯度离心,所得沉淀经检测发现含有LJ-76DNA并具有特异性DHBV内源性DNA多聚酶活性;对上述样品通过DotEIA检测DHBV核心抗原及表面抗原结果为阳性.Southernblot分析表明转染细胞内存在病毒DNA复制中间体cccDNA、ssDNA和rcDNA,而cccDNA被认为是复制活动较为活跃的标志.电镜观察转染细胞的上清发现有病毒颗粒的存在.  相似文献   

8.
从一名国内感染的艾滋病人采血,分离其外周血单核细胞(PMCs)。首先与正常的PMCs共培养,4周后检测其HIV-1p24抗原(ELISA)达到峰值。用此时的细胞及其上清分别感染Jurkat-tat、CEM、MT4细胞,可很快地在这三株细胞中检测到HIV生长,HIV在Jurkat-tat细胞中生长情况最好,同时用病人血清直接感染Jurkat-tat和MT4细胞,4周后检测其细胞上清HIV-1p24抗原(ELISA法)为阳性,但OD值很低(约为PMC共培养组的一半)。用病人的少量全血与正常PMCs共培养,得到的结果与分离病人PMCs法相近。应用间接免疫荧光法(IFA)、免疫酶法(IEA)、蛋白印迹法及HIV-1POl基因和Env基因特异引物的聚合酶链反应(PCR)等证实为HIV-1病毒。分离的HIV在Jurkat-tat细胞中连续传代,细胞被感染后2-3天即出现以大量融合细胞为主的细胞病变,感染后7-10天细胞几乎全部死亡。病毒在连续传代过程中的生长特征及致细胞病变特征不变。此病毒命名为CA-2毒株。  相似文献   

9.
应用DNA重组技术,将HuIFN-β基因插入到质粒pKKH的tac启动子下游,转化大肠杆菌JM101和JM103,经IPTG诱导,表达HuIFN-β,收集并裂解细菌,用Wish-VSV系统细胞病变抑制法检测生物学活性为2.18×108-8.7×108IU/L菌液。经初步纯化SDS-PAGE电泳可见分子量为20KD较纯的表达带。  相似文献   

10.
关于脑缺血的分子生物学研究   总被引:10,自引:0,他引:10  
脑缺血的主要直接后果是脑缺氧。脑缺血或脑缺氧除引起一系列神经化学变化与蛋白质的合成降低外,还引起热休克蛋白(HSP)和c-fos蛋白等特殊蛋白质的特殊变化。轻度缺血可引起HSP70基因转录与翻译;中度缺血只引起其转录而不翻译;重度缺血时转录与翻译均终止。轻、中度脑缺血引起c-fosmRNA剧烈而短暂的表达,c-fos、JunB、c-jun等基因转录增加;严重缺血可能因神经元死伤,导致c-fos蛋白水平降低,但局部胶质细胞c-fos诱导增强。  相似文献   

11.
12.
Up-regulation of tyrosinase gene by nitric oxide in human melanocytes   总被引:5,自引:0,他引:5  
Ultraviolet light (UV) radiation causes skin-tanning, which is thought to be mediated by stimulating the release of melanogenic factors from keratinocytes as well as other cells. Nitric oxide (NO) has been reported to be generated after UV radiation and to stimulate melanocytes as one of the melanogens. In a previous experiment by another group on melanogenesis induced by NO, increases in both tyrosinase activity and tyrosinase protein levels were observed after daily stimulation of NO for 4 days. In the present study, we investigated tyrosinase gene expression within the first 24 hr of NO-induced melanogenesis. Tyrosinase mRNA expression was found to be induced 2 hr after a single treatment with S-nitroso-N-acetyl-L-arginine. An increase of tyrosinase activity was also detected time-dependently within the 24-hr period, accompanied by an increase of tyrosinase protein levels. The induction of mRNA expression was suppressed by a cyclic guanosine 3',5'-monophosphate (cGMP)-dependent protein kinase (cGMP/PKG) inhibitor. These results suggest that the enhancement of tyrosinase gene expression via the cGMP pathway may be a primary mechanism for NO-induced melanogenesis.  相似文献   

13.
Ultraviolet light (UV) radiation causes skin‐tanning, which is thought to be mediated by stimulating the release of melanogenic factors from keratinocytes as well as other cells. Nitric oxide (NO) has been reported to be generated after UV radiation and to stimulate melanocytes as one of the melanogens. In a previous experiment by another group on melanogenesis induced by NO, increases in both tyrosinase activity and tyrosinase protein levels were observed after daily stimulation of NO for 4 days. In the present study, we investigated tyrosinase gene expression within the first 24 hr of NO‐induced melanogenesis. Tyrosinase mRNA expression was found to be induced 2 hr after a single treatment with S‐nitroso‐N‐acetyl‐ l ‐arginine. An increase of tyrosinase activity was also detected time‐dependently within the 24‐hr period, accompanied by an increase of tyrosinase protein levels. The induction of mRNA expression was suppressed by a cyclic guanosine 3′,5′‐monophosphate (cGMP)‐dependent protein kinase (cGMP/PKG) inhibitor. These results suggest that the enhancement of tyrosinase gene expression via the cGMP pathway may be a primary mechanism for NO‐induced melanogenesis.  相似文献   

14.
Suppression subtractive hybridization was used to identify genes regulated by ozone (100 nmol mol ? 1) in Pisum sativum. One novel gene (named PsUod1) was found. In addition, mRNA levels for four genes (encoding lipid transfer protein, pre‐hevein‐like protein, leucine‐rich repeat protein, and disease‐resistance response protein 230), which previously were shown to be regulated by biotic stress, increased. Finally, mRNA species for two genes (encoding extensin and pathogenesis‐related protein 4A), previously shown to be regulated by ozone in other species, were found to increase in abundance. The ozone‐specificity of the expression of these genes was studied by using UV‐B radiation. PsUod1 and the genes encoding extensin, leucine‐rich repeat protein, and disease‐resistance response protein 230, were differentially regulated when comparing ozone and UV‐B. Moreover, the mRNA levels for extensin, leucine‐rich repeat protein and disease‐resistance response protein 230 all increased under NaCl and aluminium stress and after wounding, whereas the message abundance for PsUod1 was unchanged under these stresses. Thus, in general, ozone caused changes similar to wounding, salt stress and aluminium stress, whereas UV‐B radiation regulated gene expression differently.  相似文献   

15.
The incidence of skin cancer is increasing in epidemic proportion. Although solar UV radiation is known to be the major risk factor, much information is lacking about the molecular mechanisms leading to skin cancer. To gain a deeper insight into these mechanisms, we have examined cells of a human keratinocyte cell line (HaCat) after exposure to 0.16 minimal erythema doses of UVB radiation. This dose led to an S-phase delay that was reversible 22 h postirradiation. To examine gene expression 10 h after UV irradiation, a nonradioactive differential display was employed. Three genes were identified as being down-regulated significantly. The first encodes for topoisomerase-IIbeta-binding protein 1 (expression level 5% 6 h after irradiation). This protein is associated with human topoisomerase IIbeta and appears to be necessary for DNA replication during the onset of S phase. The second gene product has previously been reported to be involved in differentiation and is therefore known as differentiation-dependent A4 protein (28% 8 h after irradiation). The third gene is XPO1 (also known as CRM1) (5% 8 h after irradiation), whose protein is involved in nuclear export of mRNA molecules. Differential expression of these genes after UV irradiation has not been reported. Because of their potential involvement in cell cycle control and differentiation, these proteins could be important for understanding the reaction of keratinocytes after exposure to UV radiation.  相似文献   

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17.
紫外线辐射增加对大豆光合作用和生长的影响   总被引:18,自引:1,他引:17       下载免费PDF全文
通过模拟南京地区自然光中有效紫外线B和紫外线A辐射,增大辐射剂量对大豆光合作用,生长及生物量形成的影响迸行了研究。3个加强的UV辐射(0.15,0.35,0.70W·m-2)处理均使大豆植株矮化,抑制根、茎、叶的生长及干物质的积累。在3个UV处理中,生物效应以0.70W·m-2处理力最大,0.15W·m-2处理影响最小。UV辐射匀能使大豆叶片光合作用下降。下降幅度随UV辐射强度的增大而增大,本文还对UV影响大豆生长的可能机制进行了探讨。  相似文献   

18.
19.
紫外照射对葡萄果实莽草酸途径相关基因表达的影响   总被引:1,自引:0,他引:1  
本文以花后11周的‘赤霞珠’葡萄果实为试材,应用荧光实时定量PCR技术,研究6种剂量的UV-A、UV-B和UV-C照射对莽草酸途径及后分支酸途径关键酶基因表达量的影响。结果表明,这些基因在转录水平上对紫外诱导的响应不同步,且有照射剂量的依赖性。一定剂量的紫外照射可显著地诱导莽草酸途径的大部分基因和后分支酸途径的VvCM-1、VvCM-2和VvAS的表达;高于或低于该剂量,表达量明显降低。不同基因对紫外诱导的响应也存在差异:3种类型紫外线对莽草酸途径入口酶的两个同源基因VvDAHPS-1和VvDAHPS-2的诱导效应均最为显著。随紫外波长减小,这两个基因受诱导表达的量有所下降。VvSK和VvCS的表达只受1.2kJ·m^-2UV-A的诱导,而不受UV-B和UV-C照射的影响,在后分支酸途径中紫外对VvCM-1表达的诱导作用明显大于VvCM-2和VvAS。  相似文献   

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