MAP kinase specifically mediates the ABA-induced H<Subscript>2</Subscript>O<Subscript>2</Subscript> generation in guard cells of<Emphasis Type="Italic">Vicia faba</Emphasis> L.

The plant hormone abscisic acid (ABA) is involved in regulating adverse physiological processes, including stomatal closure, seed development and germination, and mediating many environmental stress responses, such as drought, salinity and extreme temperatures[1,2]. In re-sponse to various stress stimuli, ABA synthesis is in-creased in plant cells, which triggers a series of physio-logical responses to adapt the stress conditions[1—3]. For example, under water deficit, ABA acts directly on…     

OsNAC2通过ABA依赖途径负调控水稻的多种非生物胁迫反应

在植物感受外界环境变化和对各种胁迫产生应答反应的过程中,转录因子是必不可少的一个环节,但是其中很多重要的成员和功能还不清楚.OsNAC2是NAC转录因子家族的一个成员,它的表达受到ABA和几种非生物胁迫的强烈诱导,如干旱和高盐.通过构建OsNAC2的过表达和RNAi株系,连同野生型共同评价OsNAC2的生物学功能.在营养生长时期,与野生型相比,过表达株系对干旱和高盐更加敏感.相反地,RNAi株系则表现更好的干旱和高盐抗性.通过芯片数据分析,发现在OsNAC2过表达植株中,许多胁迫相关基因的表达量均下调.这些结果说明OsNAC2负调控水稻的非生物胁迫反应,并且可能是ABA依赖通路中的一个重要因子.     

Oscillatory change of SR-protein kinase activities during oocyte maturation meiosis in fish

The SR-protein kinase activity was analyzed and the cytological changes were observed during oocyte maturation in bisexual transparent color crucian carp ( Carassius auratus color variety) . The results revealed that the SR-protein kinase activity was sensitive to the artificially induced spawning hormones, and the change of oscillatory activity was similar to that of the maturation-promoting factor (MPF) kinase that regulates meiotic cell cycle in fish.     

Crystal structures of catalytic and regulatory subunits of rat protein kinase CK2

Protein kinase CK2 consists of two catalytic subunits (CK2α) and two regulatory subunits (CK2β). Here, we report the crystal structures of rat CK2α mutant (rCK2α-△C, 1—335) and CK2β (rCK2β). The overall topology of rCK2α-△C and rCK2β are very similar to the human enzyme, although large structural differences could be observed in the N-terminal domain of rCK2α-△C. Our reported structure of rCK2α-△C is in the close conformation state while the counterpart hCK2α is in the open conformation state, indi- cating ...     

Regulation of mouse blastocyst adhesion,outgrowth and matrix metalloproteinase—2 by focal adhesion kinase

The interaction of extracellular matrix-integrin markedly influences the adhesion,outgrowth,differentiation and expression of serine proteinases by the blastocyst,so it is regarded as a vital factor in blastocyst implantation.Although the mechanism of extracellular interactions between extracellular matrix and integrins has been well elucidated,the roles of the signaling molecules in the extracellular matrix-integrin signal transduction pathway in blastocyst implantation are unknown.This limits the understanding of blastocyst implantation and ECM-integrin signal transduction pathway.In the present study,in vitro blastocyst culture and indirect immunocytochemistry,matrix metalloproteinases(MMPs) zymography and antisense oligodeoxynucleotide(ODN) were used to investigate the expression of a fundamental molecule of integrin-dependent signal transduction pathways,focal adhesion kinase(FAK),in mouse blastocysts and its influence on mouse blastocyst adhesion,outgrowth and MMP-2.The results showed that mouse blastocysts expressed FAK.FAK protein was clustered in the peripheral migrating trophoblast cells and dispersed in the central area of blastocyst outgrowth.Fibronectin triggered pro-MMP-2 and 64kD MMP-2 activities.The antisense ODN to FAK attnuated pro-MMP-2 and 64kD MMP-2 activites which decreased abruptly and tended to disappear with increasting concentrations of the antisense ODN.Both mouse blastocyst adhesion and outgrowth on fibronectin were also influenced by the antisense ODN.Up to 20μg/mL of the antisense ODN concentration,the adhesion and out-growth rates were decreased in a dose-dependent manner.The results indicated that FAK influenced mouse blastocyst adhesion,outgrowth and MMP-2 activity by intracellular signal transduction.In other words,FAK regulates mouse implantation in terms of blastocyst adhesive and invasive abilities.     

Src激酶抑制剂FB2抗前列腺癌作用研究

探讨Src激酶抑制剂FB2抗前列腺癌的作用及机制.整体动物实验观察FB2对人前列腺癌PC-3细胞在裸鼠异体中生长的影响;MMT、克隆原形成、细胞黏附试验观察FB2对肿瘤细胞增殖、黏附的影响;流式细胞术分析FB2对细胞周期的影响;Western blot观察细胞及组织内Src及p-Src表达.实验结果表明FB2抑制PC-3细胞裸鼠移植瘤的生长;FB2抑制PC-3细胞增殖及对基底膜成分的黏附,并将细胞周期阻滞于G1期;机制研究表明,FB2抑制PC-3细胞及瘤组织中Src激酶Tyr416磷酸化.因此Src激酶抑制剂FB2在体内外均有较强的抗前列腺癌作用,其机制可能与抑制Src激酶Tyr416磷酸化有关.     

紫外分光光度技术测定植物细胞中H2O2的含量

利用H2O2在24Onm处有吸收光谱的特性，建立了快速测定植物活细胞产生H2O2的方法．同时利用该技术进一步定量检测了ABA诱导蚕豆气孔保卫细胞H2O2的产生．     

Immunohistochemical localization of Ca2+/calmodulin-dependent kinase in tobacco

The existence of Ca²⁺/calmodulin-dependent kinase (CaM kinase, CaMK) in tobacco is verified immuno- logically and its distribution in different tissues of tobacco is studied. It has been demonstrated that CaMK is mainly distributed in early developing anthers, developing ovules and embryos, lateral root primordium, apical meristem and leaf primordium of buds and mesophyll cells and developing vascular bundles of leaves. There is enormous CaM kinase distributed in leaf epidermis fair cells and guard cells of stomas too. Little kinase is found in mature stem or root cells. The distribution properties of CaM kinase in tobacco are consistent with those of CaM, suggesting that there exists the Ca²⁺ signal transduction pathway mediated by CaM kinase in tobacco and it plays an important role in the plant growth and development.     

Ca2+ -CaM与乙烯调节草莓果实NAD激酶和NADP磷酸酶活性的关系

用外源乙烯单独以及乙烯分别与钙离子通道阻塞剂异博定(Verapamil,Vp)、钙调素拮抗剂氯丙嗪(Chloropromaize,CPZ)、三氟拉嗪(Trifluoperazine,TFP)处理乳白期草莓果实12 h,移去乙烯之后在空气中继续放置24h,测定果实乙烯释放率、NAD激酶活性及NADP磷酸酶活性的变化.结果表明,外源乙烯能诱导草莓果实乙烯大量合成,比对照(未经任何处理)提高420%和73%,抑制NAD激酶活性约20%和40%,对NADP磷酸酶影响不明显.Vp、CPZ和TFP均能逆转外源乙烯诱导的乙烯合成以及对NAD激酶活性的抑制作用,表明乙烯可能通过抑制草莓果实中NAD激酶活性从而促进和加快果实成熟衰老,Ca2 、CaM可能介导草莓果实的乙烯信号转导.     

Ca~(2+)和CaM在IAA诱导小麦芽鞘伸长中的作用

应用 Ca~(2+)抑制剂和 CaM(钙调素)拮抗剂,对 Ca~(2+)和 CaM 在 IAA诱导小麦芽鞘伸长中的作用进行了研究.结果表明,小于0.5 mmol/L Ca~(2+)可明显促进小麦芽鞘切段伸长,并能加强 IAA 对伸长的促进,1mmol/L 以上Ca~(2+)则有抑制伸长的作用.Ca~(2+)通道抑制剂 Co~(2+)和 La~(3+)、CaM 拮抗剂CPZ(氯丙嗪)明显抑制芽鞘切段伸长,也降低 IAA 促进伸长的效应.因而,可以认为 Ca~(2+)介入 IAA 诱导细胞的伸长过程,Ca~(2+)通过 CaM 发挥其生理功能.     

基于分子对接研究吲哚咔唑类小分子对Tie-2/VEGFR2的双效抑制作用模式*

 运用分子对接技术研究了吲哚咔唑类小分子对人血管内皮生长因子受体2(VEGFR2)和人血管生成素受体Tie-2(ANG-R-Tie-2)的双效抑制作用模式。研究结果表明,吲哚咔唑类小分子的双效抑制作用主要源于两种受体相似的活性口袋,小分子与两者的铰链区均可形成氢键,使其催化活性受到抑制,从而抑制肿瘤细胞的生长。抑制活性的差异主要源于活性口袋的细微差异所导致疏水、静电等相互作用的不同。其中,疏水作用的差异是影响配体选择性的主要原因,静电作用、氢键及空间位阻对结合稳定也有一定影响。该文的研究结果为多靶点酪氨酸激酶小分子抑制剂的设计及提高激酶抑制剂的选择性提供了重要的理论依据。     

水稻抗稻瘟病基因Pi-ta与Pi-ta2之间的关系

该研究以含抗稻瘟病基因pi-ta和pi-ta2的水稻品种Katy和Kaybonnet为供体亲本的4个F2群体(含2516个单株)为材料,利用已建立的pi-ta显性标记与pi-ta2微卫星标记进行分子检测,结果发现,所有含pi-ta基因的单株都具有pi-ta2,不含pi-ta基因的单株也无pi-ta2,这表明,这两个基因紧密连锁或等位;稻瘟病菌(Magnaporthe grisea)人工接种试验发现所有抗病单株都含pi-ta基因,而感病单株则无.由此表明,在含2516个单株的F2群体中没有发生抗病基因的重组,这进一步验证这两个抗病基因等位或紧密连锁.     

水稻组蛋白脱乙酰化酶HD2 HDACs蛋白质的生物信息学分析

HD2 HDACs家族成员是植物特异性的组蛋白脱乙酰化酶并参与基因的转录调控.本研究利用生物信息学方法对水稻组蛋白脱乙酰化酶HD2 HDACs家族成员(HDT701、HDT702、HDT2201和HDT2202)的生物学功能进行研究.结果表明,HD2 HDACs家族成员位于不同的染色体上,分布于细胞的不同部位;它们编码的蛋白均含有依赖于cAMP-和cGMP的蛋白激酶、蛋白激酶C、酪蛋白激酶II与酰胺化4个相同的位点;它们均无跨膜区,都为不稳定的亲水性蛋白质,都无信号肽.多序列比对发现粳稻与籼稻HD2 HDACs的同源性非常高;水稻HD2 HDACs蛋白质的结构域比较特殊;这些蛋白可能参与植物的基因复制、信号传导、转录过程和免疫应答等过程.     

应用小鼠胸腺细胞法与脾细胞法测定IL—2活性的比较

分别应用ＣｏｎＡ激活的小鼠胸腺细胞增殖法和脾细胞增殖法对样品内白细胞介素－２（ＩＬ－２）的活性进行生物学测定．细胞增殖状况以３Ｈ－ＴｄＲ掺入强度显示，并对实验条件进行了探讨．结果表明；添加氢化考的松（ＨＣ）的胸腺细胞法适用于检测培养物上清内的ＩＬ－２活性，其实验操作较脾细胞法更为省时省事     

水稻OsRhoGDI2基因RNA干扰载体的构建

水稻OsRhoGDI2是通过酵母双杂交筛选到的小G蛋白Rho家族成员OsRacD互作蛋白的编码基因,为了研究OsRhoGDI2与OsRacD的相互作用及其在水稻发育中的功能联系,本研究基于序列比对的提示,选择了OsRhoGDI2基因长度为285 bp的特异区段,分别以正向和反向插入中间载体pKANNIBAL中,并亚克隆...     

肺结核及病变转归患者血清MMP-2及TIMP-2检测的临床意义

[目的]探讨肺结核（PTB）及病变转归患者血清中基质金属蛋白酶2（MMP-2）及基质蛋白酶组织抑制剂2（TIMP-2）含量关系,以期为监测PTB患者病情变化及判断结核病治疗效果提供理论依据.[方法]酶联免疫（ELISA）法检测60 例肺结核患者及 20 例无肺部疾病患者（对照组）的血清MMP-2 及 TIMP-2含量,同时进行肺功能检查.[结果]浸润型肺结核（MMP-2:157.52±21.04;TIMP-2:185.15±14.08）及慢性纤维空洞型肺结核（MMP-2:169.48±18.13;TIMP-2:208.60±17.06）显著高于肺功能正常及其他类型的结核病患者（差异显著,均有统计学意义（p<0.01））.当PTB疾病逐渐转归并且痊愈,MMP-2 与TIMP-2的含量比例逐渐接近肺功能正常组.[结论]MMP-2、TIMP-2的含量关系在监测及治疗该两类结核病上具有一定的临床价值.     

水稻基因组中U2snRNA基因连锁的分析

根据Ｕ２ｎＲＮＡ基因的保守性和结构特点设计引物,通过ＰＣＲ法扩增Ｕ２ｓｎＲＮＡ连锁基因间区的ＤＮＡ片段并进行顺序分析,证实在水稻中至少存在一组Ｕ２ｓｎＲＮＡ连锁基因。对水稻总ＤＮＡ的ＰＣＲ分析结果表明,水稻中可能还存在其他形式的连锁基因。ＰＣＲ方法可以有效地应用于结构保守基因的连锁分析中。     

细胞周期蛋白质依赖性激酶CDK2多克隆抗体的制备和鉴定

我们采用PCR技术合成编码CDK2肽段的基因,将其置于谷胱甘肽转移酶（GST）编码基因的下游,在IPTG诱导下,于E．coli中诱导表达了GST-CDK2肽融合蛋白质,以此融合蛋白质作为免疫原免疫家兔制备抗CDK2的多克隆抗体,经Western Blot检测证明：该抗体能够特异地识别CDK2蛋白质,可作为CDK2的特异性检测抗体,用于研究细胞周期和细胞凋亡进程中CDK2的作用．     

Involvement of NADPH oxidase NtrbohD in the rapid production of H2O2 induced by ABA in cultured tobacco cell line BY-2

The mechanisms for the production of hydrogen peroxide (H₂O₂) induced by abscisic acid (ABA) were investigated in suspension culture cells of tobacco BY-2 cells. The results showed that the immediate generation of H₂O₂, which was mainly derived from superoxide dismutase-catalyzed dismutation of superoxide radical, was significantly induced by ABA. Furthermore, treatment of the cultured tobacco cells with ABA resulted in a time-dependent quick increase in plasma membrane (PM) NADPH oxidase activity, which coincided on time and magnitude with the elevation in ABA-induced accumulation of H₂O₂. Moreover, these enhanced effects were pronouncedly inhibited by two NADPH oxidase inhibitor, diphenylene iodonium and imidazole, suggesting that PM NADPH oxidase is involved in the rapid accumulation of ₂O₂ in cultured tobacco cells. In addition, analysis of the expression level of NtrbohD, a PM NADPH oxidase gene in tobacco, by RT-PCR and protein gel blot revealed that the gene at both mRNA and protein levels was upregulated by ABA, indicating that NtrbohD participates in the ABA-stimulated rapid production of H₂O₂ in tobacco culture cells. Taken together, these findings suggest that ABA induces the rapid accumulation of reactive oxygen species via NADPH oxidase in suspension culture cells of tobacco, and that NADPH oxidase and H₂O₂ appear to be important components in ABA signal transduction pathway in plants.